/****** * name: arkenfox user.js * date: 23 November 2021 * version 94 * url: https://github.com/arkenfox/user.js * license: MIT: https://github.com/arkenfox/user.js/blob/master/LICENSE.txt * README: 1. Consider using Tor Browser if it meets your needs or fits your threat model * https://www.torproject.org/about/torusers.html.en 2. Required reading: Overview, Backing Up, Implementing, and Maintenance entries * https://github.com/arkenfox/user.js/wiki 3. If you skipped step 2, return to step 2 4. Make changes * There are often trade-offs and conflicts between security vs privacy vs anti-tracking and these need to be balanced against functionality & convenience & breakage * Some site breakage and unintended consequences will happen. Everyone's experience will differ e.g. some user data is erased on exit (section 2800), change this to suit your needs * While not 100% definitive, search for "[SETUP" tags e.g. third party images/videos not loading on some sites? check 1601 * Take the wiki link in step 2 and read the Troubleshooting entry 5. Some tag info [SETUP-SECURITY] it's one item, read it [SETUP-WEB] can cause some websites to break [SETUP-CHROME] changes how Firefox itself behaves (i.e. not directly website related) 6. Override Recipes: https://github.com/arkenfox/user.js/issues/1080 * RELEASES: https://github.com/arkenfox/user.js/releases * It is best to use the arkenfox release that is optimized for and matches your Firefox version * EVERYONE: each release - run prefsCleaner to reset prefs made inactive, including deprecated (9999s) ESR91 - If you are not using arkenfox v91... (not a definitive list) - 9999: switch the appropriate deprecated section(s) back on * INDEX: 0100: STARTUP 0200: GEOLOCATION / LANGUAGE / LOCALE 0300: QUIETER FOX 0400: SAFE BROWSING 0600: BLOCK IMPLICIT OUTBOUND 0700: DNS / DoH / PROXY / SOCKS / IPv6 0800: LOCATION BAR / SEARCH BAR / SUGGESTIONS / HISTORY / FORMS 0900: PASSWORDS 1000: DISK AVOIDANCE 1200: HTTPS (SSL/TLS / OCSP / CERTS / HPKP) 1400: FONTS 1600: HEADERS / REFERERS 1700: CONTAINERS 2000: PLUGINS / MEDIA / WEBRTC 2300: WEB WORKERS 2400: DOM (DOCUMENT OBJECT MODEL) 2600: MISCELLANEOUS 2700: PERSISTENT STORAGE 2800: SHUTDOWN & SANITIZING 4000: FPI (FIRST PARTY ISOLATION) 4500: RFP (RESIST FINGERPRINTING) 5000: OPTIONAL OPSEC 5500: OPTIONAL HARDENING 6000: DON'T TOUCH 7000: DON'T BOTHER 8000: DON'T BOTHER: NON-RFP 9000: PERSONAL 9999: DEPRECATED / REMOVED / LEGACY / RENAMED ******/ /* START: internal custom pref to test for syntax errors * [NOTE] Not all syntax errors cause parsing to abort i.e. reaching the last debug pref * no longer necessarily means that all prefs have been applied. Check the console right * after startup for any warnings/error messages related to non-applied prefs * [1] https://blog.mozilla.org/nnethercote/2018/03/09/a-new-preferences-parser-for-firefox/ ***/ user_pref("_user.js.parrot", "START: Oh yes, the Norwegian Blue... what's wrong with it?"); /* 0000: disable about:config warning ***/ user_pref("browser.aboutConfig.showWarning", false); /*** [SECTION 0100]: STARTUP ***/ user_pref("_user.js.parrot", "0100 syntax error: the parrot's dead!"); /* 0101: disable default browser check * [SETTING] General>Startup>Always check if Firefox is your default browser ***/ user_pref("browser.shell.checkDefaultBrowser", false); /* 0102: set startup page [SETUP-CHROME] * 0=blank, 1=home, 2=last visited page, 3=resume previous session * [NOTE] Session Restore is cleared with history (2811, 2812), and not used in Private Browsing mode * [SETTING] General>Startup>Restore previous session ***/ user_pref("browser.startup.page", 0); /* 0103: set HOME+NEWWINDOW page * about:home=Activity Stream (default, see 0105), custom URL, about:blank * [SETTING] Home>New Windows and Tabs>Homepage and new windows ***/ user_pref("browser.startup.homepage", "about:blank"); /* 0104: set NEWTAB page * true=Activity Stream (default, see 0105), false=blank page * [SETTING] Home>New Windows and Tabs>New tabs ***/ user_pref("browser.newtabpage.enabled", false); user_pref("browser.newtab.preload", false); /* 0105: disable some Activity Stream items * Activity Stream is the default homepage/newtab based on metadata and browsing behavior * [SETTING] Home>Firefox Home Content>... to show/hide what you want ***/ user_pref("browser.newtabpage.activity-stream.feeds.telemetry", false); user_pref("browser.newtabpage.activity-stream.telemetry", false); user_pref("browser.newtabpage.activity-stream.feeds.snippets", false); // [DEFAULT: false] user_pref("browser.newtabpage.activity-stream.feeds.section.topstories", false); user_pref("browser.newtabpage.activity-stream.section.highlights.includePocket", false); user_pref("browser.newtabpage.activity-stream.showSponsored", false); user_pref("browser.newtabpage.activity-stream.feeds.discoverystreamfeed", false); // [FF66+] user_pref("browser.newtabpage.activity-stream.showSponsoredTopSites", false); // [FF83+] /* 0106: clear default topsites * [NOTE] This does not block you from adding your own ***/ user_pref("browser.newtabpage.activity-stream.default.sites", ""); /*** [SECTION 0200]: GEOLOCATION / LANGUAGE / LOCALE ***/ user_pref("_user.js.parrot", "0200 syntax error: the parrot's definitely deceased!"); /* 0201: use Mozilla geolocation service instead of Google if permission is granted [FF74+] * Optionally enable logging to the console (defaults to false) ***/ user_pref("geo.provider.network.url", "https://location.services.mozilla.com/v1/geolocate?key=%MOZILLA_API_KEY%"); // user_pref("geo.provider.network.logging.enabled", true); // [HIDDEN PREF] /* 0202: disable using the OS's geolocation service ***/ user_pref("geo.provider.ms-windows-location", false); // [WINDOWS] user_pref("geo.provider.use_corelocation", false); // [MAC] user_pref("geo.provider.use_gpsd", false); // [LINUX] /* 0203: disable region updates * [1] https://firefox-source-docs.mozilla.org/toolkit/modules/toolkit_modules/Region.html ***/ user_pref("browser.region.network.url", ""); // [FF78+] user_pref("browser.region.update.enabled", false); // [FF79+] /* 0204: set search region * [NOTE] May not be hidden if Firefox has changed your settings due to your region (0203) ***/ // user_pref("browser.search.region", "US"); // [HIDDEN PREF] /* 0210: set preferred language for displaying pages * [SETTING] General>Language and Appearance>Language>Choose your preferred language... * [TEST] https://addons.mozilla.org/about ***/ user_pref("intl.accept_languages", "en-US, en"); /* 0211: use US English locale regardless of the system locale * [SETUP-WEB] May break some input methods e.g xim/ibus for CJK languages [1] * [1] https://bugzilla.mozilla.org/buglist.cgi?bug_id=867501,1629630 ***/ user_pref("javascript.use_us_english_locale", true); // [HIDDEN PREF] /*** [SECTION 0300]: QUIETER FOX ***/ user_pref("_user.js.parrot", "0300 syntax error: the parrot's not pinin' for the fjords!"); /** UPDATES ***/ /* 0301: disable auto-INSTALLING Firefox updates [NON-WINDOWS] * [NOTE] You will still get prompts to update, and should do so in a timely manner * [SETTING] General>Firefox Updates>Check for updates but let you choose to install them ***/ user_pref("app.update.auto", false); /* 0302: disable auto-INSTALLING Firefox updates via a background service [FF90+] [WINDOWS] * [SETTING] General>Firefox Updates>Automatically install updates>When Firefox is not running * [1] https://support.mozilla.org/kb/enable-background-updates-firefox-windows ***/ user_pref("app.update.background.scheduling.enabled", false); /* 0303: disable auto-CHECKING for extension and theme updates ***/ // user_pref("extensions.update.enabled", false); /* 0304: disable auto-INSTALLING extension and theme updates (after the check in 0303) * [SETTING] about:addons>Extensions>[cog-wheel-icon]>Update Add-ons Automatically (toggle) ***/ // user_pref("extensions.update.autoUpdateDefault", false); /* 0305: disable extension metadata * used when installing/updating an extension, and in daily background update checks: * when false, extension detail tabs will have no description ***/ // user_pref("extensions.getAddons.cache.enabled", false); /* 0306: disable search engine updates (e.g. OpenSearch) * [NOTE] This does not affect Mozilla's built-in or Web Extension search engines ***/ user_pref("browser.search.update", false); /** RECOMMENDATIONS ***/ /* 0320: disable recommendation pane in about:addons (uses Google Analytics) ***/ user_pref("extensions.getAddons.showPane", false); // [HIDDEN PREF] /* 0321: disable recommendations in about:addons' Extensions and Themes panes [FF68+] ***/ user_pref("extensions.htmlaboutaddons.recommendations.enabled", false); /* 0322: disable personalized Extension Recommendations in about:addons and AMO [FF65+] * [NOTE] This pref has no effect when Health Reports (0331) are disabled * [SETTING] Privacy & Security>Firefox Data Collection & Use>Allow Firefox to make personalized extension recommendations * [1] https://support.mozilla.org/kb/personalized-extension-recommendations ***/ user_pref("browser.discovery.enabled", false); /** TELEMETRY ***/ /* 0330: disable new data submission [FF41+] * If disabled, no policy is shown or upload takes place, ever * [1] https://bugzilla.mozilla.org/1195552 ***/ user_pref("datareporting.policy.dataSubmissionEnabled", false); /* 0331: disable Health Reports * [SETTING] Privacy & Security>Firefox Data Collection & Use>Allow Firefox to send technical... data ***/ user_pref("datareporting.healthreport.uploadEnabled", false); /* 0332: disable telemetry * The "unified" pref affects the behaviour of the "enabled" pref * - If "unified" is false then "enabled" controls the telemetry module * - If "unified" is true then "enabled" only controls whether to record extended data * [NOTE] "toolkit.telemetry.enabled" is now LOCKED to reflect prerelease (true) or release builds (false) [2] * [1] https://firefox-source-docs.mozilla.org/toolkit/components/telemetry/telemetry/internals/preferences.html * [2] https://medium.com/georg-fritzsche/data-preference-changes-in-firefox-58-2d5df9c428b5 ***/ user_pref("toolkit.telemetry.unified", false); user_pref("toolkit.telemetry.enabled", false); // see [NOTE] user_pref("toolkit.telemetry.server", "data:,"); user_pref("toolkit.telemetry.archive.enabled", false); user_pref("toolkit.telemetry.newProfilePing.enabled", false); // [FF55+] user_pref("toolkit.telemetry.shutdownPingSender.enabled", false); // [FF55+] user_pref("toolkit.telemetry.updatePing.enabled", false); // [FF56+] user_pref("toolkit.telemetry.bhrPing.enabled", false); // [FF57+] Background Hang Reporter user_pref("toolkit.telemetry.firstShutdownPing.enabled", false); // [FF57+] /* 0333: disable Telemetry Coverage * [1] https://blog.mozilla.org/data/2018/08/20/effectively-measuring-search-in-firefox/ ***/ user_pref("toolkit.telemetry.coverage.opt-out", true); // [HIDDEN PREF] user_pref("toolkit.coverage.opt-out", true); // [FF64+] [HIDDEN PREF] user_pref("toolkit.coverage.endpoint.base", ""); /* 0334: disable PingCentre telemetry (used in several System Add-ons) [FF57+] * Defense-in-depth: currently covered by 0331 ***/ user_pref("browser.ping-centre.telemetry", false); /** STUDIES ***/ /* 0340: disable Studies * [SETTING] Privacy & Security>Firefox Data Collection & Use>Allow Firefox to install and run studies ***/ user_pref("app.shield.optoutstudies.enabled", false); /* 0341: disable Normandy/Shield [FF60+] * Shield is a telemetry system that can push and test "recipes" * [1] https://mozilla.github.io/normandy/ ***/ user_pref("app.normandy.enabled", false); user_pref("app.normandy.api_url", ""); /** CRASH REPORTS ***/ /* 0350: disable Crash Reports ***/ user_pref("breakpad.reportURL", ""); user_pref("browser.tabs.crashReporting.sendReport", false); // [FF44+] // user_pref("browser.crashReports.unsubmittedCheck.enabled", false); // [FF51+] [DEFAULT: false] /* 0351: enforce no submission of backlogged Crash Reports [FF58+] * [SETTING] Privacy & Security>Firefox Data Collection & Use>Allow Firefox to send backlogged crash reports ***/ user_pref("browser.crashReports.unsubmittedCheck.autoSubmit2", false); // [DEFAULT: false] /** OTHER ***/ /* 0360: disable Captive Portal detection * [1] https://www.eff.org/deeplinks/2017/08/how-captive-portals-interfere-wireless-security-and-privacy ***/ user_pref("captivedetect.canonicalURL", ""); user_pref("network.captive-portal-service.enabled", false); // [FF52+] /* 0361: disable Network Connectivity checks [FF65+] * [1] https://bugzilla.mozilla.org/1460537 ***/ user_pref("network.connectivity-service.enabled", false); /* 0362: enforce disabling of Web Compatibility Reporter [FF56+] * Web Compatibility Reporter adds a "Report Site Issue" button to send data to Mozilla ***/ user_pref("extensions.webcompat-reporter.enabled", false); // [DEFAULT: false] /*** [SECTION 0400]: SAFE BROWSING (SB) SB has taken many steps to preserve privacy. If required, a full url is never sent to Google, only a part-hash of the prefix, hidden with noise of other real part-hashes. Firefox takes measures such as stripping out identifying parameters and since SBv4 (FF57+) doesn't even use cookies. (#Turn on browser.safebrowsing.debug to monitor this activity) [1] https://feeding.cloud.geek.nz/posts/how-safe-browsing-works-in-firefox/ [2] https://wiki.mozilla.org/Security/Safe_Browsing [3] https://support.mozilla.org/kb/how-does-phishing-and-malware-protection-work ***/ user_pref("_user.js.parrot", "0400 syntax error: the parrot's passed on!"); /* 0401: disable SB (Safe Browsing) * [WARNING] Do this at your own risk! These are the master switches * [SETTING] Privacy & Security>Security>... Block dangerous and deceptive content ***/ // user_pref("browser.safebrowsing.malware.enabled", false); // user_pref("browser.safebrowsing.phishing.enabled", false); /* 0402: disable SB checks for downloads (both local lookups + remote) * This is the master switch for the safebrowsing.downloads* prefs (0403, 0404) * [SETTING] Privacy & Security>Security>... "Block dangerous downloads" ***/ // user_pref("browser.safebrowsing.downloads.enabled", false); /* 0403: disable SB checks for downloads (remote) * To verify the safety of certain executable files, Firefox may submit some information about the * file, including the name, origin, size and a cryptographic hash of the contents, to the Google * Safe Browsing service which helps Firefox determine whether or not the file should be blocked * [SETUP-SECURITY] If you do not understand this, or you want this protection, then override it ***/ user_pref("browser.safebrowsing.downloads.remote.enabled", false); user_pref("browser.safebrowsing.downloads.remote.url", ""); /* 0404: disable SB checks for unwanted software * [SETTING] Privacy & Security>Security>... "Warn you about unwanted and uncommon software" ***/ // user_pref("browser.safebrowsing.downloads.remote.block_potentially_unwanted", false); // user_pref("browser.safebrowsing.downloads.remote.block_uncommon", false); /* 0405: disable "ignore this warning" on SB warnings [FF45+] * If clicked, it bypasses the block for that session. This is a means for admins to enforce SB * [TEST] see github wiki APPENDIX A: Test Sites: Section 5 * [1] https://bugzilla.mozilla.org/1226490 ***/ // user_pref("browser.safebrowsing.allowOverride", false); /*** [SECTION 0600]: BLOCK IMPLICIT OUTBOUND [not explicitly asked for - e.g. clicked on] ***/ user_pref("_user.js.parrot", "0600 syntax error: the parrot's no more!"); /* 0601: disable link prefetching * [1] https://developer.mozilla.org/docs/Web/HTTP/Link_prefetching_FAQ ***/ user_pref("network.prefetch-next", false); /* 0602: disable DNS prefetching * [1] https://developer.mozilla.org/docs/Web/HTTP/Headers/X-DNS-Prefetch-Control ***/ user_pref("network.dns.disablePrefetch", true); // user_pref("network.dns.disablePrefetchFromHTTPS", true); // [DEFAULT: true] /* 0603: disable predictor / prefetching ***/ user_pref("network.predictor.enabled", false); // user_pref("network.predictor.enable-prefetch", false); // [FF48+] [DEFAULT: false] /* 0604: disable link-mouseover opening connection to linked server * [1] https://news.slashdot.org/story/15/08/14/2321202/how-to-quash-firefoxs-silent-requests ***/ user_pref("network.http.speculative-parallel-limit", 0); /* 0605: enforce no "Hyperlink Auditing" (click tracking) * [1] https://www.bleepingcomputer.com/news/software/major-browsers-to-prevent-disabling-of-click-tracking-privacy-risk/ ***/ // user_pref("browser.send_pings", false); // [DEFAULT: false] /*** [SECTION 0700]: DNS / DoH / PROXY / SOCKS / IPv6 ***/ user_pref("_user.js.parrot", "0700 syntax error: the parrot's given up the ghost!"); /* 0701: disable IPv6 * IPv6 can be abused, especially with MAC addresses, and can leak with VPNs: assuming * your ISP and/or router and/or website is IPv6 capable. Most sites will fall back to IPv4 * [STATS] Firefox telemetry (July 2021) shows ~10% of all connections are IPv6 * [NOTE] This is an application level fallback. Disabling IPv6 is best done at an * OS/network level, and/or configured properly in VPN setups. If you are not masking your IP, * then this won't make much difference. If you are masking your IP, then it can only help. * [NOTE] PHP defaults to IPv6 with "localhost". Use "php -S 127.0.0.1:PORT" * [TEST] https://ipleak.org/ * [1] https://www.internetsociety.org/tag/ipv6-security/ (Myths 2,4,5,6) ***/ user_pref("network.dns.disableIPv6", true); /* 0702: set the proxy server to do any DNS lookups when using SOCKS * e.g. in Tor, this stops your local DNS server from knowing your Tor destination * as a remote Tor node will handle the DNS request * [1] https://trac.torproject.org/projects/tor/wiki/doc/TorifyHOWTO/WebBrowsers ***/ user_pref("network.proxy.socks_remote_dns", true); /* 0703: disable using UNC (Uniform Naming Convention) paths [FF61+] * [SETUP-CHROME] Can break extensions for profiles on network shares * [1] https://gitlab.torproject.org/tpo/applications/tor-browser/-/issues/26424 ***/ user_pref("network.file.disable_unc_paths", true); // [HIDDEN PREF] /* 0704: disable GIO as a potential proxy bypass vector [FF60+] * Gvfs/GIO has a set of supported protocols like obex, network, archive, computer, dav, cdda, * gphoto2, trash, etc. By default only smb and sftp protocols are accepted so far (as of FF64) * [1] https://bugzilla.mozilla.org/1433507 * [2] https://en.wikipedia.org/wiki/GVfs * [3] https://en.wikipedia.org/wiki/GIO_(software) ***/ user_pref("network.gio.supported-protocols", ""); // [HIDDEN PREF] /* 0705: disable proxy direct failover for system requests [FF91+] * [WARNING] Default true is a security feature against malicious extensions [1] * [SETUP-CHROME] If you use a proxy and you trust your extensions * [1] https://blog.mozilla.org/security/2021/10/25/securing-the-proxy-api-for-firefox-add-ons/ ***/ // user_pref("network.proxy.failover_direct", false); /* 0710: disable DNS-over-HTTPS (DoH) rollout [FF60+] * 0=off by default, 2=TRR (Trusted Recursive Resolver) first, 3=TRR only, 5=explicitly off * see "doh-rollout.home-region": USA Feb 2020, Canada July 2021 [3] * [1] https://hacks.mozilla.org/2018/05/a-cartoon-intro-to-dns-over-https/ * [2] https://wiki.mozilla.org/Security/DOH-resolver-policy * [3] https://blog.mozilla.org/mozilla/news/firefox-by-default-dns-over-https-rollout-in-canada/ * [4] https://www.eff.org/deeplinks/2020/12/dns-doh-and-odoh-oh-my-year-review-2020 ***/ // user_pref("network.trr.mode", 5); /*** [SECTION 0800]: LOCATION BAR / SEARCH BAR / SUGGESTIONS / HISTORY / FORMS ***/ user_pref("_user.js.parrot", "0800 syntax error: the parrot's ceased to be!"); /* 0801: disable location bar using search * Don't leak URL typos to a search engine, give an error message instead * Examples: "secretplace,com", "secretplace/com", "secretplace com", "secret place.com" * [NOTE] This does not affect explicit user action such as using search buttons in the * dropdown, or using keyword search shortcuts you configure in options (e.g. "d" for DuckDuckGo) * [SETUP-CHROME] If you don't, or rarely, type URLs, or you use a default search * engine that respects privacy, then you probably don't need this ***/ user_pref("keyword.enabled", false); /* 0802: disable location bar domain guessing * domain guessing intercepts DNS "hostname not found errors" and resends a * request (e.g. by adding www or .com). This is inconsistent use (e.g. FQDNs), does not work * via Proxy Servers (different error), is a flawed use of DNS (TLDs: why treat .com * as the 411 for DNS errors?), privacy issues (why connect to sites you didn't * intend to), can leak sensitive data (e.g. query strings: e.g. Princeton attack), * and is a security risk (e.g. common typos & malicious sites set up to exploit this) ***/ user_pref("browser.fixup.alternate.enabled", false); /* 0803: display all parts of the url in the location bar ***/ user_pref("browser.urlbar.trimURLs", false); /* 0804: disable live search suggestions * [NOTE] Both must be true for the location bar to work * [SETUP-CHROME] Change these if you trust and use a privacy respecting search engine * [SETTING] Search>Provide search suggestions | Show search suggestions in address bar results ***/ user_pref("browser.search.suggest.enabled", false); user_pref("browser.urlbar.suggest.searches", false); /* 0805: disable location bar making speculative connections [FF56+] * [1] https://bugzilla.mozilla.org/1348275 ***/ user_pref("browser.urlbar.speculativeConnect.enabled", false); /* 0806: disable location bar leaking single words to a DNS provider **after searching** [FF78+] * 0=never resolve single words, 1=heuristic (default), 2=always resolve * [1] https://bugzilla.mozilla.org/1642623 ***/ user_pref("browser.urlbar.dnsResolveSingleWordsAfterSearch", 0); /* 0807: disable location bar contextual suggestions [FF92+] * [SETTING] Privacy & Security>Address Bar>Contextual Suggestions * [1] https://blog.mozilla.org/data/2021/09/15/data-and-firefox-suggest/ ***/ user_pref("browser.urlbar.suggest.quicksuggest", false); user_pref("browser.urlbar.suggest.quicksuggest.sponsored", false); /* 0808: disable tab-to-search [FF85+] * Alternatively, you can exclude on a per-engine basis by unchecking them in Options>Search * [SETTING] Privacy & Security>Address Bar>When using the address bar, suggest>Search engines ***/ // user_pref("browser.urlbar.suggest.engines", false); /* 0810: disable search and form history * [SETUP-WEB] Be aware that autocomplete form data can be read by third parties [1][2] * [NOTE] We also clear formdata on exit (2811) * [SETTING] Privacy & Security>History>Custom Settings>Remember search and form history * [1] https://blog.mindedsecurity.com/2011/10/autocompleteagain.html * [2] https://bugzilla.mozilla.org/381681 ***/ user_pref("browser.formfill.enable", false); /* 0811: disable Form Autofill * [NOTE] Stored data is NOT secure (uses a JSON file) * [NOTE] Heuristics controls Form Autofill on forms without @autocomplete attributes * [SETTING] Privacy & Security>Forms and Autofill>Autofill addresses * [1] https://wiki.mozilla.org/Firefox/Features/Form_Autofill ***/ user_pref("extensions.formautofill.addresses.enabled", false); // [FF55+] user_pref("extensions.formautofill.available", "off"); // [FF56+] user_pref("extensions.formautofill.creditCards.available", false); // [FF57+] user_pref("extensions.formautofill.creditCards.enabled", false); // [FF56+] user_pref("extensions.formautofill.heuristics.enabled", false); // [FF55+] /* 0820: disable coloring of visited links * [SETUP-HARDEN] Bulk rapid history sniffing was mitigated in 2010 [1][2]. Slower and more expensive * redraw timing attacks were largely mitigated in FF77+ [3]. Using RFP (4501) further hampers timing * attacks. Don't forget clearing history on exit (2811). However, social engineering [2#limits][4][5] * and advanced targeted timing attacks could still produce usable results * [1] https://developer.mozilla.org/docs/Web/CSS/Privacy_and_the_:visited_selector * [2] https://dbaron.org/mozilla/visited-privacy * [3] https://bugzilla.mozilla.org/1632765 * [4] https://earthlng.github.io/testpages/visited_links.html (see github wiki APPENDIX A on how to use) * [5] https://lcamtuf.blogspot.com/2016/08/css-mix-blend-mode-is-bad-for-keeping.html ***/ // user_pref("layout.css.visited_links_enabled", false); /*** [SECTION 0900]: PASSWORDS [1] https://support.mozilla.org/kb/use-primary-password-protect-stored-logins-and-pas ***/ user_pref("_user.js.parrot", "0900 syntax error: the parrot's expired!"); /* 0901: set when Firefox should prompt for the primary password * 0=once per session (default), 1=every time it's needed, 2=after n minutes (0902) ***/ user_pref("security.ask_for_password", 2); /* 0902: set how long in minutes Firefox should remember the primary password (0901) ***/ user_pref("security.password_lifetime", 5); // [DEFAULT: 30] /* 0903: disable auto-filling username & password form fields * can leak in cross-site forms *and* be spoofed * [NOTE] Username & password is still available when you enter the field * [SETTING] Privacy & Security>Logins and Passwords>Autofill logins and passwords * [1] https://freedom-to-tinker.com/2017/12/27/no-boundaries-for-user-identities-web-trackers-exploit-browser-login-managers/ ***/ user_pref("signon.autofillForms", false); /* 0904: disable formless login capture for Password Manager [FF51+] ***/ user_pref("signon.formlessCapture.enabled", false); /* 0905: limit (or disable) HTTP authentication credentials dialogs triggered by sub-resources [FF41+] * hardens against potential credentials phishing * 0 = don't allow sub-resources to open HTTP authentication credentials dialogs * 1 = don't allow cross-origin sub-resources to open HTTP authentication credentials dialogs * 2 = allow sub-resources to open HTTP authentication credentials dialogs (default) ***/ user_pref("network.auth.subresource-http-auth-allow", 1); /* 0906: enforce no automatic authentication on Microsoft sites [FF91+] [WINDOWS 10+] * [SETTING] Privacy & Security>Logins and Passwords>Allow Windows single sign-on for... * [1] https://support.mozilla.org/kb/windows-sso ***/ user_pref("network.http.windows-sso.enabled", false); // [DEFAULT: false] /*** [SECTION 1000]: DISK AVOIDANCE ***/ user_pref("_user.js.parrot", "1000 syntax error: the parrot's gone to meet 'is maker!"); /* 1001: disable disk cache * [SETUP-CHROME] If you think disk cache helps perf, then feel free to override this * [NOTE] We also clear cache on exit (2811) ***/ user_pref("browser.cache.disk.enable", false); /* 1002: disable media cache from writing to disk in Private Browsing * [NOTE] MSE (Media Source Extensions) are already stored in-memory in PB * [SETUP-WEB] ESR78: playback might break on subsequent loading (1650281) ***/ user_pref("browser.privatebrowsing.forceMediaMemoryCache", true); // [FF75+] user_pref("media.memory_cache_max_size", 65536); /* 1003: disable storing extra session data [SETUP-CHROME] * define on which sites to save extra session data such as form content, cookies and POST data * 0=everywhere, 1=unencrypted sites, 2=nowhere ***/ user_pref("browser.sessionstore.privacy_level", 2); /* 1004: set the minimum interval between session save operations * Increasing this can help on older machines and some websites, as well as reducing writes [1] * [1] https://bugzilla.mozilla.org/1304389 ***/ user_pref("browser.sessionstore.interval", 30000); // [DEFAULT: 15000] /* 1005: disable automatic Firefox start and session restore after reboot [FF62+] [WINDOWS] * [1] https://bugzilla.mozilla.org/603903 ***/ user_pref("toolkit.winRegisterApplicationRestart", false); /* 1006: disable favicons in shortcuts * URL shortcuts use a cached randomly named .ico file which is stored in your * profile/shortcutCache directory. The .ico remains after the shortcut is deleted * If set to false then the shortcuts use a generic Firefox icon ***/ user_pref("browser.shell.shortcutFavicons", false); /*** [SECTION 1200]: HTTPS (SSL/TLS / OCSP / CERTS / HPKP) Your cipher and other settings can be used in server side fingerprinting [TEST] https://www.ssllabs.com/ssltest/viewMyClient.html [TEST] https://browserleaks.com/ssl [TEST] https://ja3er.com/ [1] https://www.securityartwork.es/2017/02/02/tls-client-fingerprinting-with-bro/ ***/ user_pref("_user.js.parrot", "1200 syntax error: the parrot's a stiff!"); /** SSL (Secure Sockets Layer) / TLS (Transport Layer Security) ***/ /* 1201: require safe negotiation * Blocks connections (SSL_ERROR_UNSAFE_NEGOTIATION) to servers that don't support RFC 5746 [2] * as they're potentially vulnerable to a MiTM attack [3]. A server without RFC 5746 can be * safe from the attack if it disables renegotiations but the problem is that the browser can't * know that. Setting this pref to true is the only way for the browser to ensure there will be * no unsafe renegotiations on the channel between the browser and the server. * [STATS] SSL Labs (July 2021) reports over 99% of sites have secure renegotiation [4] * [1] https://wiki.mozilla.org/Security:Renegotiation * [2] https://tools.ietf.org/html/rfc5746 * [3] https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2009-3555 * [4] https://www.ssllabs.com/ssl-pulse/ ***/ user_pref("security.ssl.require_safe_negotiation", true); /* 1203: reset TLS 1.0 and 1.1 downgrades i.e. session only ***/ user_pref("security.tls.version.enable-deprecated", false); // [DEFAULT: false] /* 1206: disable TLS1.3 0-RTT (round-trip time) [FF51+] * [1] https://github.com/tlswg/tls13-spec/issues/1001 * [2] https://blog.cloudflare.com/tls-1-3-overview-and-q-and-a/ ***/ user_pref("security.tls.enable_0rtt_data", false); /** OCSP (Online Certificate Status Protocol) [1] https://scotthelme.co.uk/revocation-is-broken/ [2] https://blog.mozilla.org/security/2013/07/29/ocsp-stapling-in-firefox/ ***/ /* 1211: enforce OCSP fetching to confirm current validity of certificates * 0=disabled, 1=enabled (default), 2=enabled for EV certificates only * OCSP (non-stapled) leaks information about the sites you visit to the CA (cert authority) * It's a trade-off between security (checking) and privacy (leaking info to the CA) * [NOTE] This pref only controls OCSP fetching and does not affect OCSP stapling * [SETTING] Privacy & Security>Security>Certificates>Query OCSP responder servers... * [1] https://en.wikipedia.org/wiki/Ocsp ***/ user_pref("security.OCSP.enabled", 1); // [DEFAULT: 1] /* 1212: set OCSP fetch failures (non-stapled, see 1211) to hard-fail [SETUP-WEB] * When a CA cannot be reached to validate a cert, Firefox just continues the connection (=soft-fail) * Setting this pref to true tells Firefox to instead terminate the connection (=hard-fail) * It is pointless to soft-fail when an OCSP fetch fails: you cannot confirm a cert is still valid (it * could have been revoked) and/or you could be under attack (e.g. malicious blocking of OCSP servers) * [1] https://blog.mozilla.org/security/2013/07/29/ocsp-stapling-in-firefox/ * [2] https://www.imperialviolet.org/2014/04/19/revchecking.html ***/ user_pref("security.OCSP.require", true); /** CERTS / HPKP (HTTP Public Key Pinning) ***/ /* 1220: disable or limit SHA-1 certificates * 0 = allow all * 1 = block all * 3 = only allow locally-added roots (e.g. anti-virus) (default) * 4 = only allow locally-added roots or for certs in 2015 and earlier * [SETUP-CHROME] If you have problems, update your software: SHA-1 is obsolete * [1] https://blog.mozilla.org/security/2016/10/18/phasing-out-sha-1-on-the-public-web/ ***/ user_pref("security.pki.sha1_enforcement_level", 1); /* 1221: disable Windows 8.1's Microsoft Family Safety cert [FF50+] [WINDOWS] * 0=disable detecting Family Safety mode and importing the root * 1=only attempt to detect Family Safety mode (don't import the root) * 2=detect Family Safety mode and import the root * [1] https://gitlab.torproject.org/tpo/applications/tor-browser/-/issues/21686 ***/ user_pref("security.family_safety.mode", 0); /* 1223: enable strict pinning * PKP (Public Key Pinning) 0=disabled, 1=allow user MiTM (such as your antivirus), 2=strict * [SETUP-WEB] If you rely on an AV (antivirus) to protect your web browsing * by inspecting ALL your web traffic, then leave at current default=1 * [1] https://gitlab.torproject.org/tpo/applications/tor-browser/-/issues/16206 ***/ user_pref("security.cert_pinning.enforcement_level", 2); /* 1224: enable CRLite [FF73+] * In FF84+ it covers valid certs and in mode 2 doesn't fall back to OCSP * [1] https://bugzilla.mozilla.org/buglist.cgi?bug_id=1429800,1670985 * [2] https://blog.mozilla.org/security/tag/crlite/ ***/ user_pref("security.remote_settings.crlite_filters.enabled", true); user_pref("security.pki.crlite_mode", 2); /** MIXED CONTENT ***/ /* 1241: disable insecure passive content (such as images) on https pages [SETUP-WEB] ***/ user_pref("security.mixed_content.block_display_content", true); /* 1244: enable HTTPS-Only mode in all windows [FF76+] * When the top-level is HTTPS, insecure subresources are also upgraded (silent fail) * [SETTING] to add site exceptions: Padlock>HTTPS-Only mode>On (after "Continue to HTTP Site") * [SETTING] Privacy & Security>HTTPS-Only Mode (and manage exceptions) * [TEST] http://example.com [upgrade] * [TEST] http://neverssl.com/ [no upgrade] ***/ user_pref("dom.security.https_only_mode", true); // [FF76+] // user_pref("dom.security.https_only_mode_pbm", true); // [FF80+] /* 1245: enable HTTPS-Only mode for local resources [FF77+] ***/ // user_pref("dom.security.https_only_mode.upgrade_local", true); /* 1246: disable HTTP background requests [FF82+] * When attempting to upgrade, if the server doesn't respond within 3 seconds, * Firefox sends HTTP requests in order to check if the server supports HTTPS or not * This is done to avoid waiting for a timeout which takes 90 seconds * [1] https://bugzilla.mozilla.org/buglist.cgi?bug_id=1642387,1660945 ***/ user_pref("dom.security.https_only_mode_send_http_background_request", false); /** UI (User Interface) ***/ /* 1270: display warning on the padlock for "broken security" (if 1201 is false) * Bug: warning padlock not indicated for subresources on a secure page! [2] * [1] https://wiki.mozilla.org/Security:Renegotiation * [2] https://bugzilla.mozilla.org/1353705 ***/ user_pref("security.ssl.treat_unsafe_negotiation_as_broken", true); /* 1271: control "Add Security Exception" dialog on SSL warnings * 0=do neither, 1=pre-populate url, 2=pre-populate url + pre-fetch cert (default) * [1] https://github.com/pyllyukko/user.js/issues/210 ***/ user_pref("browser.ssl_override_behavior", 1); /* 1272: display advanced information on Insecure Connection warning pages * only works when it's possible to add an exception * i.e. it doesn't work for HSTS discrepancies (https://subdomain.preloaded-hsts.badssl.com/) * [TEST] https://expired.badssl.com/ ***/ user_pref("browser.xul.error_pages.expert_bad_cert", true); /* 1273: display "Not Secure" text on HTTP sites ***/ user_pref("security.insecure_connection_text.enabled", true); // [FF60+] /*** [SECTION 1400]: FONTS ***/ user_pref("_user.js.parrot", "1400 syntax error: the parrot's bereft of life!"); /* 1401: disable rendering of SVG OpenType fonts ***/ user_pref("gfx.font_rendering.opentype_svg.enabled", false); /* 1402: limit font visibility (Windows, Mac, some Linux) [FF94+] * Uses hardcoded lists with two parts: kBaseFonts + kLangPackFonts [1], bundled fonts are auto-allowed * In normal windows: uses the first applicable: RFP (4506) over TP over Standard * In Private Browsing windows: uses the most restrictive between normal and private * 1=only base system fonts, 2=also fonts from optional language packs, 3=also user-installed fonts * [1] https://searchfox.org/mozilla-central/search?path=StandardFonts*.inc ***/ // user_pref("layout.css.font-visibility.private", 1); // user_pref("layout.css.font-visibility.standard", 1); // user_pref("layout.css.font-visibility.trackingprotection", 1); /*** [SECTION 1600]: HEADERS / REFERERS Expect some breakage e.g. banks: use an extension if you need precise control full URI: https://example.com:8888/foo/bar.html?id=1234 scheme+host+port+path: https://example.com:8888/foo/bar.html scheme+host+port: https://example.com:8888 [1] https://feeding.cloud.geek.nz/posts/tweaking-referrer-for-privacy-in-firefox/ ***/ user_pref("_user.js.parrot", "1600 syntax error: the parrot rests in peace!"); /* 1601: control when to send a cross-origin referer * 0=always (default), 1=only if base domains match, 2=only if hosts match * [SETUP-WEB] Known to cause issues with older modems/routers and some sites e.g vimeo, icloud, instagram ***/ user_pref("network.http.referer.XOriginPolicy", 2); /* 1602: control the amount of cross-origin information to send [FF52+] * 0=send full URI (default), 1=scheme+host+port+path, 2=scheme+host+port ***/ user_pref("network.http.referer.XOriginTrimmingPolicy", 2); /* 1603: enable the DNT (Do Not Track) HTTP header * [NOTE] DNT is enforced with Enhanced Tracking Protection (2710) * [SETTING] Privacy & Security>Enhanced Tracking Protection>Send websites a "Do Not Track" signal... ***/ // user_pref("privacy.donottrackheader.enabled", true); /*** [SECTION 1700]: CONTAINERS Check out Temporary Containers [2], read the article [3], and visit the wiki/repo [4] [1] https://wiki.mozilla.org/Security/Contextual_Identity_Project/Containers [2] https://addons.mozilla.org/firefox/addon/temporary-containers/ [3] https://medium.com/@stoically/enhance-your-privacy-in-firefox-with-temporary-containers-33925cd6cd21 [4] https://github.com/stoically/temporary-containers/wiki ***/ user_pref("_user.js.parrot", "1700 syntax error: the parrot's bit the dust!"); /* 1701: enable Container Tabs and its UI setting [FF50+] * [SETTING] General>Tabs>Enable Container Tabs ***/ user_pref("privacy.userContext.enabled", true); user_pref("privacy.userContext.ui.enabled", true); /* 1702: set behaviour on "+ Tab" button to display container menu on left click [FF74+] * [NOTE] The menu is always shown on long press and right click * [SETTING] General>Tabs>Enable Container Tabs>Settings>Select a container for each new tab ***/ // user_pref("privacy.userContext.newTabContainerOnLeftClick.enabled", true); /*** [SECTION 2000]: PLUGINS / MEDIA / WEBRTC ***/ user_pref("_user.js.parrot", "2000 syntax error: the parrot's snuffed it!"); /* 2001: disable WebRTC (Web Real-Time Communication) * [SETUP-WEB] WebRTC can leak your private network address from behind your VPN, but if this * is not your threat model, and you want Real-Time Communication, this is the pref for you ***/ user_pref("media.peerconnection.enabled", false); /* 2002: limit WebRTC private network address leaks * In FF70+ these settings match Mode 4 (Mode 3 in older versions) [3] * [TEST] https://browserleaks.com/webrtc * [1] https://bugzilla.mozilla.org/buglist.cgi?bug_id=1189041,1297416,1452713 * [2] https://wiki.mozilla.org/Media/WebRTC/Privacy * [3] https://tools.ietf.org/html/draft-ietf-rtcweb-ip-handling-12#section-5.2 ***/ user_pref("media.peerconnection.ice.default_address_only", true); user_pref("media.peerconnection.ice.no_host", true); // [FF51+] user_pref("media.peerconnection.ice.proxy_only_if_behind_proxy", true); // [FF70+] /* 2020: disable GMP (Gecko Media Plugins) * [1] https://wiki.mozilla.org/GeckoMediaPlugins ***/ // user_pref("media.gmp-provider.enabled", false); /* 2021: disable widevine CDM (Content Decryption Module) * [NOTE] This is covered by the EME master switch (2022) ***/ // user_pref("media.gmp-widevinecdm.enabled", false); /* 2022: disable all DRM content (EME: Encryption Media Extension) * [SETUP-WEB] e.g. Netflix, Amazon Prime, Hulu, HBO, Disney+, Showtime, Starz, DirectTV * [SETTING] General>DRM Content>Play DRM-controlled content * [TEST] https://bitmovin.com/demos/drm * [1] https://www.eff.org/deeplinks/2017/10/drms-dead-canary-how-we-just-lost-web-what-we-learned-it-and-what-we-need-do-next ***/ user_pref("media.eme.enabled", false); /* 2030: disable autoplay of HTML5 media [FF63+] * 0=Allow all, 1=Block non-muted media (default), 5=Block all * [NOTE] You can set exceptions under site permissions * [SETTING] Privacy & Security>Permissions>Autoplay>Settings>Default for all websites ***/ // user_pref("media.autoplay.default", 5); /* 2031: disable autoplay of HTML5 media if you interacted with the site [FF78+] * 0=sticky (default), 1=transient, 2=user * Firefox's Autoplay Policy Documentation [PDF] is linked below via SUMO * [NOTE] If you have trouble with some video sites, then add an exception (2030) * [1] https://support.mozilla.org/questions/1293231 ***/ user_pref("media.autoplay.blocking_policy", 2); /*** [SECTION 2300]: WEB WORKERS A worker is a JS "background task" running in a global context, i.e. it is different from the current window. Workers can spawn new workers (must be the same origin & scheme), including service and shared workers. Shared workers can be utilized by multiple scripts and communicate between browsing contexts (windows/tabs/iframes) and can even control your cache. [1] Web Workers: https://developer.mozilla.org/docs/Web/API/Web_Workers_API [2] Worker: https://developer.mozilla.org/docs/Web/API/Worker [3] Service Worker: https://developer.mozilla.org/docs/Web/API/Service_Worker_API [4] SharedWorker: https://developer.mozilla.org/docs/Web/API/SharedWorker [5] ChromeWorker: https://developer.mozilla.org/docs/Web/API/ChromeWorker [6] Notifications: https://support.mozilla.org/questions/1165867#answer-981820 ***/ user_pref("_user.js.parrot", "2300 syntax error: the parrot's off the twig!"); /* 2302: disable service workers [FF32, FF44-compat] * Service workers essentially act as proxy servers that sit between web apps, and the * browser and network, are event driven, and can control the web page/site they are associated * with, intercepting and modifying navigation and resource requests, and caching resources. * [NOTE] Service workers require HTTPS, have no DOM access, and are not supported in PB mode [1] * [SETUP-WEB] Disabling service workers will break some sites. This pref is required true for * service worker notifications (2304), push notifications (disabled, 2305) and service worker * cache (2740). If you enable this pref, then check those settings as well * [1] https://bugzilla.mozilla.org/show_bug.cgi?id=1320796#c7 ***/ user_pref("dom.serviceWorkers.enabled", false); /* 2304: disable Web Notifications * [NOTE] Web Notifications can also use service workers (2302) and are behind a prompt (7002) * [1] https://developer.mozilla.org/docs/Web/API/Notifications_API ***/ // user_pref("dom.webnotifications.enabled", false); // [FF22+] // user_pref("dom.webnotifications.serviceworker.enabled", false); // [FF44+] /* 2305: disable Push Notifications [FF44+] * Push is an API that allows websites to send you (subscribed) messages even when the site * isn't loaded, by pushing messages to your userAgentID through Mozilla's Push Server * [NOTE] Push requires service workers (2302) to subscribe to and display, and is behind * a prompt (7002). Disabling service workers alone doesn't stop Firefox polling the * Mozilla Push Server. To remove all subscriptions, reset your userAgentID. * [1] https://support.mozilla.org/kb/push-notifications-firefox * [2] https://developer.mozilla.org/docs/Web/API/Push_API ***/ user_pref("dom.push.enabled", false); // user_pref("dom.push.userAgentID", ""); /*** [SECTION 2400]: DOM (DOCUMENT OBJECT MODEL) ***/ user_pref("_user.js.parrot", "2400 syntax error: the parrot's kicked the bucket!"); /* 2401: disable "Confirm you want to leave" dialog on page close * Does not prevent JS leaks of the page close event * [1] https://developer.mozilla.org/docs/Web/Events/beforeunload ***/ user_pref("dom.disable_beforeunload", true); /* 2402: prevent scripts from moving and resizing open windows ***/ user_pref("dom.disable_window_move_resize", true); /* 2403: block popup windows * [SETTING] Privacy & Security>Permissions>Block pop-up windows ***/ user_pref("dom.disable_open_during_load", true); /* 2404: limit events that can cause a popup [SETUP-WEB] ***/ user_pref("dom.popup_allowed_events", "click dblclick mousedown pointerdown"); /*** [SECTION 2600]: MISCELLANEOUS ***/ user_pref("_user.js.parrot", "2600 syntax error: the parrot's run down the curtain!"); /* 2601: prevent accessibility services from accessing your browser [RESTART] * [1] https://support.mozilla.org/kb/accessibility-services ***/ user_pref("accessibility.force_disabled", 1); /* 2602: disable sending additional analytics to web servers * [1] https://developer.mozilla.org/docs/Web/API/Navigator/sendBeacon ***/ user_pref("beacon.enabled", false); /* 2603: remove temp files opened with an external application * [1] https://bugzilla.mozilla.org/302433 ***/ user_pref("browser.helperApps.deleteTempFileOnExit", true); /* 2604: disable page thumbnail collection ***/ user_pref("browser.pagethumbnails.capturing_disabled", true); // [HIDDEN PREF] /* 2606: disable UITour backend so there is no chance that a remote page can use it ***/ user_pref("browser.uitour.enabled", false); user_pref("browser.uitour.url", ""); /* 2607: disable various developer tools in browser context * [SETTING] Devtools>Advanced Settings>Enable browser chrome and add-on debugging toolboxes * [1] https://github.com/pyllyukko/user.js/issues/179#issuecomment-246468676 ***/ user_pref("devtools.chrome.enabled", false); /* 2608: reset remote debugging to disabled * [1] https://gitlab.torproject.org/tpo/applications/tor-browser/-/issues/16222 ***/ user_pref("devtools.debugger.remote-enabled", false); // [DEFAULT: false] /* 2611: disable middle mouse click opening links from clipboard * [1] https://gitlab.torproject.org/tpo/applications/tor-browser/-/issues/10089 ***/ user_pref("middlemouse.contentLoadURL", false); /* 2615: disable websites overriding Firefox's keyboard shortcuts [FF58+] * 0 (default) or 1=allow, 2=block * [SETTING] to add site exceptions: Ctrl+I>Permissions>Override Keyboard Shortcuts ***/ // user_pref("permissions.default.shortcuts", 2); /* 2616: remove special permissions for certain mozilla domains [FF35+] * [1] resource://app/defaults/permissions ***/ user_pref("permissions.manager.defaultsUrl", ""); /* 2617: remove webchannel whitelist ***/ user_pref("webchannel.allowObject.urlWhitelist", ""); /* 2619: use Punycode in Internationalized Domain Names to eliminate possible spoofing * [SETUP-WEB] Might be undesirable for non-latin alphabet users since legitimate IDN's are also punycoded * [TEST] https://www.xn--80ak6aa92e.com/ (www.apple.com) * [1] https://wiki.mozilla.org/IDN_Display_Algorithm * [2] https://en.wikipedia.org/wiki/IDN_homograph_attack * [3] https://cve.mitre.org/cgi-bin/cvekey.cgi?keyword=punycode+firefox * [4] https://www.xudongz.com/blog/2017/idn-phishing/ ***/ user_pref("network.IDN_show_punycode", true); /* 2620: enforce PDFJS, disable PDFJS scripting [SETUP-CHROME] * This setting controls if the option "Display in Firefox" is available in the setting below * and by effect controls whether PDFs are handled in-browser or externally ("Ask" or "Open With") * PROS: pdfjs is lightweight, open source, and more secure/vetted than most * Exploits are rare (one serious case in seven years), treated seriously and patched quickly. * It doesn't break "state separation" of browser content (by not sharing with OS, independent apps). * It maintains disk avoidance and application data isolation. It's convenient. You can still save to disk. * CONS: You may prefer a different pdf reader for security reasons * CAVEAT: JS can still force a pdf to open in-browser by bundling its own code * [SETTING] General>Applications>Portable Document Format (PDF) ***/ user_pref("pdfjs.disabled", false); // [DEFAULT: false] user_pref("pdfjs.enableScripting", false); // [FF86+] /* 2621: disable links launching Windows Store on Windows 8/8.1/10 [WINDOWS] ***/ user_pref("network.protocol-handler.external.ms-windows-store", false); /* 2623: disable permissions delegation [FF73+] * Currently applies to cross-origin geolocation, camera, mic and screen-sharing * permissions, and fullscreen requests. Disabling delegation means any prompts * for these will show/use their correct 3rd party origin * [1] https://groups.google.com/forum/#!topic/mozilla.dev.platform/BdFOMAuCGW8/discussion ***/ user_pref("permissions.delegation.enabled", false); /** DOWNLOADS ***/ /* 2651: enable user interaction for security by always asking where to download * [SETUP-CHROME] On Android this blocks longtapping and saving images * [SETTING] General>Downloads>Always ask you where to save files ***/ user_pref("browser.download.useDownloadDir", false); /* 2652: disable adding downloads to the system's "recent documents" list ***/ user_pref("browser.download.manager.addToRecentDocs", false); /** EXTENSIONS ***/ /* 2660: lock down allowed extension directories * [SETUP-CHROME] This will break extensions, language packs, themes and any other * XPI files which are installed outside of profile and application directories * [1] https://mike.kaply.com/2012/02/21/understanding-add-on-scopes/ * [1] https://archive.is/DYjAM (archived) ***/ user_pref("extensions.enabledScopes", 5); // [HIDDEN PREF] user_pref("extensions.autoDisableScopes", 15); // [DEFAULT: 15] /* 2661: disable bypassing 3rd party extension install prompts [FF82+] * [1] https://bugzilla.mozilla.org/buglist.cgi?bug_id=1659530,1681331 ***/ user_pref("extensions.postDownloadThirdPartyPrompt", false); /* 2662: disable webextension restrictions on certain mozilla domains (you also need 4503) [FF60+] * [1] https://bugzilla.mozilla.org/buglist.cgi?bug_id=1384330,1406795,1415644,1453988 ***/ // user_pref("extensions.webextensions.restrictedDomains", ""); /*** [SECTION 2700]: PERSISTENT STORAGE Data SET by websites including cookies : profile\cookies.sqlite localStorage : profile\webappsstore.sqlite indexedDB : profile\storage\default serviceWorkers : [NOTE] indexedDB and serviceWorkers are not available in Private Browsing Mode [NOTE] Blocking cookies also blocks websites access to: localStorage (incl. sessionStorage), indexedDB, sharedWorker, and serviceWorker (and therefore service worker cache and notifications) If you set a site exception for cookies (either "Allow" or "Allow for Session") then they become accessible to websites except shared/service workers where the cookie setting must be "Allow" ***/ user_pref("_user.js.parrot", "2700 syntax error: the parrot's joined the bleedin' choir invisible!"); /* 2701: disable or isolate 3rd-party cookies and site-data [SETUP-WEB] * 0 = Accept cookies and site data * 1 = (Block) All third-party cookies * 2 = (Block) All cookies * 3 = (Block) Cookies from unvisited websites * 4 = (Block) Cross-site tracking cookies (default) * 5 = (Isolate All) Cross-site cookies (TCP: Total Cookie Protection / dFPI: dynamic FPI) [1] (FF86+) * Option 5 with FPI enabled (4001) is ignored and not shown, and option 4 used instead * [NOTE] You can set cookie exceptions under site permissions or use an extension * [NOTE] Enforcing category to custom ensures ETP related prefs are always honored * [SETTING] Privacy & Security>Enhanced Tracking Protection>Custom>Cookies * [1] https://blog.mozilla.org/security/2021/02/23/total-cookie-protection/ ***/ user_pref("network.cookie.cookieBehavior", 1); user_pref("browser.contentblocking.category", "custom"); /* 2710: enable Enhanced Tracking Protection (ETP) in all windows * [SETTING] Privacy & Security>Enhanced Tracking Protection>Custom>Tracking content * [SETTING] to add site exceptions: Urlbar>ETP Shield * [SETTING] to manage site exceptions: Options>Privacy & Security>Enhanced Tracking Protection>Manage Exceptions ***/ user_pref("privacy.trackingprotection.enabled", true); /* 2711: enable various ETP lists ***/ user_pref("privacy.trackingprotection.socialtracking.enabled", true); // user_pref("privacy.trackingprotection.cryptomining.enabled", true); // [DEFAULT: true] // user_pref("privacy.trackingprotection.fingerprinting.enabled", true); // [DEFAULT: true] /* 2740: disable service worker cache and cache storage * [NOTE] We clear service worker cache on exit (2811) * [1] https://w3c.github.io/ServiceWorker/#privacy ***/ // user_pref("dom.caches.enabled", false); /* 2750: disable Storage API [FF51+] * The API gives sites the ability to find out how much space they can use, how much * they are already using, and even control whether or not they need to be alerted * before the user agent disposes of site data in order to make room for other things. * [1] https://developer.mozilla.org/docs/Web/API/StorageManager * [2] https://developer.mozilla.org/docs/Web/API/Storage_API * [3] https://blog.mozilla.org/l10n/2017/03/07/firefox-l10n-report-aurora-54/ ***/ // user_pref("dom.storageManager.enabled", false); /* 2755: disable Storage Access API [FF65+] * [1] https://developer.mozilla.org/docs/Web/API/Storage_Access_API ***/ // user_pref("dom.storage_access.enabled", false); /* 2760: enable Local Storage Next Generation (LSNG) [FF65+] ***/ user_pref("dom.storage.next_gen", true); // [DEFAULT: true FF92+] /*** [SECTION 2800]: SHUTDOWN & SANITIZING ***/ user_pref("_user.js.parrot", "2800 syntax error: the parrot's bleedin' demised!"); /** COOKIES + SITE DATA : ALLOWS EXCEPTIONS ***/ /* 2801: delete cookies and site data on exit * 0=keep until they expire (default), 2=keep until you close Firefox * [SETTING] Privacy & Security>Cookies and Site Data>Delete cookies and site data when Firefox is closed * [SETTING] to add site exceptions: Ctrl+I>Permissions>Cookies>Allow * If using FPI the syntax must be https://example.com/^firstPartyDomain=example.com * [SETTING] to manage site exceptions: Options>Privacy & Security>Permissions>Settings ***/ user_pref("network.cookie.lifetimePolicy", 2); /* 2802: delete cache on exit [FF96+] * [NOTE] We already disable disk cache (1001) and clear on exit (2811) which is more robust * [1] https://bugzilla.mozilla.org/1671182 ***/ // user_pref("privacy.clearsitedata.cache.enabled", true); /* 2803: set third-party cookies to session-only * [NOTE] .sessionOnly overrides .nonsecureSessionOnly except when .sessionOnly=false and * .nonsecureSessionOnly=true. This allows you to keep HTTPS cookies, but session-only HTTP ones * [1] https://feeding.cloud.geek.nz/posts/tweaking-cookies-for-privacy-in-firefox/ ***/ user_pref("network.cookie.thirdparty.sessionOnly", true); user_pref("network.cookie.thirdparty.nonsecureSessionOnly", true); // [FF58+] /** SANITIZE ON SHUTDOWN : ALL OR NOTHING ***/ /* 2810: enable Firefox to clear items on shutdown (2811) * [SETTING] Privacy & Security>History>Custom Settings>Clear history when Firefox closes ***/ user_pref("privacy.sanitize.sanitizeOnShutdown", true); /* 2811: set/enforce what items to clear on shutdown (if 2810 is true) [SETUP-CHROME] * sanitizingOnShutdown is all or nothing, it does not allow exceptions (1681701) * [NOTE] If "history" is true, downloads will also be cleared * [NOTE] "sessions": Active Logins: refers to HTTP Basic Authentication [1], not logins via cookies * [NOTE] "offlineApps": Offline Website Data: localStorage, service worker cache, QuotaManager (IndexedDB, asm-cache) * [SETTING] Privacy & Security>History>Custom Settings>Clear history when Firefox closes>Settings * [1] https://en.wikipedia.org/wiki/Basic_access_authentication ***/ user_pref("privacy.clearOnShutdown.cache", true); // [DEFAULT: true] user_pref("privacy.clearOnShutdown.downloads", true); // [DEFAULT: true] user_pref("privacy.clearOnShutdown.formdata", true); // [DEFAULT: true] user_pref("privacy.clearOnShutdown.history", true); // [DEFAULT: true] user_pref("privacy.clearOnShutdown.sessions", true); // [DEFAULT: true] user_pref("privacy.clearOnShutdown.cookies", false); user_pref("privacy.clearOnShutdown.offlineApps", true); // user_pref("privacy.clearOnShutdown.siteSettings", false); // [DEFAULT: false] Site Preferences /* 2812: reset default items to clear with Ctrl-Shift-Del (to match 2811) [SETUP-CHROME] * This dialog can also be accessed from the menu History>Clear Recent History * Firefox remembers your last choices. This will reset them when you start Firefox * [NOTE] Regardless of what you set "downloads" to, as soon as the dialog * for "Clear Recent History" is opened, it is synced to the same as "history" ***/ user_pref("privacy.cpd.cache", true); // [DEFAULT: true] user_pref("privacy.cpd.formdata", true); // [DEFAULT: true] user_pref("privacy.cpd.history", true); // [DEFAULT: true] user_pref("privacy.cpd.sessions", true); // [DEFAULT: true] user_pref("privacy.cpd.cookies", false); user_pref("privacy.cpd.offlineApps", true); // user_pref("privacy.cpd.downloads", true); // not used, see note above // user_pref("privacy.cpd.passwords", false); // [DEFAULT: false] this is not listed // user_pref("privacy.cpd.siteSettings", false); // [DEFAULT: false] Site Preferences /* 2813: clear Session Restore data when sanitizing on shutdown or manually [FF34+] * [NOTE] Not needed if Session Restore is not used (0102) or it is already cleared with history (2811) * [NOTE] privacy.clearOnShutdown.openWindows prevents resuming from crashes (also see 5008) * [NOTE] privacy.cpd.openWindows has a bug that causes an additional window to open ***/ // user_pref("privacy.clearOnShutdown.openWindows", true); // user_pref("privacy.cpd.openWindows", true); /* 2814: reset default "Time range to clear" for "Clear Recent History" (2812) * Firefox remembers your last choice. This will reset the value when you start Firefox * 0=everything, 1=last hour, 2=last two hours, 3=last four hours, 4=today * [NOTE] Values 5 (last 5 minutes) and 6 (last 24 hours) are not listed in the dropdown, * which will display a blank value, and are not guaranteed to work ***/ user_pref("privacy.sanitize.timeSpan", 0); /*** [SECTION 4000]: FPI (FIRST PARTY ISOLATION) 1278037 - indexedDB (FF51+) 1277803 - favicons (FF52+) 1264562 - OCSP cache (FF52+) 1268726 - Shared Workers (FF52+) 1316283 - SSL session cache (FF52+) 1317927 - media cache (FF53+) 1323644 - HSTS and HPKP (FF54+) 1334690 - HTTP Alternative Services (FF54+) 1334693 - SPDY/HTTP2 (FF55+) 1337893 - DNS cache (FF55+) 1344170 - blob: URI (FF55+) 1300671 - data:, about: URLs (FF55+) 1473247 - IP addresses (FF63+) 1542309 - top-level domain URLs when host is in the public suffix list (FF68+) 1506693 - pdfjs range-based requests (FF68+) 1330467 - site permissions (FF69+) 1534339 - IPv6 (FF73+) 1721858 - WebSocket (FF92+) ***/ user_pref("_user.js.parrot", "4000 syntax error: the parrot's pegged out"); /* 4001: enable First Party Isolation [FF51+] * [SETUP-WEB] Breaks some cross-origin logins * [1] https://bugzilla.mozilla.org/buglist.cgi?bug_id=1260931,1299996 ***/ user_pref("privacy.firstparty.isolate", true); /* 4002: enforce FPI restriction for window.opener [FF54+] * [NOTE] Setting this to false may reduce the breakage in 4001 * FF65+ blocks postMessage with targetOrigin "*" if originAttributes don't match. But * to reduce breakage it ignores the 1st-party domain (FPD) originAttribute [2][3] * The 2nd pref removes that limitation and will only allow communication if FPDs also match * [1] https://bugzilla.mozilla.org/1319773#c22 * [2] https://bugzilla.mozilla.org/1492607 * [3] https://developer.mozilla.org/docs/Web/API/Window/postMessage ***/ // user_pref("privacy.firstparty.isolate.restrict_opener_access", true); // [DEFAULT: true] // user_pref("privacy.firstparty.isolate.block_post_message", true); /* 4003: enable scheme with FPI [FF78+] * [NOTE] Experimental: existing data and site permissions are incompatible * and some site exceptions may not work e.g. HTTPS-only mode (1244) ***/ // user_pref("privacy.firstparty.isolate.use_site", true); /*** [SECTION 4500]: RFP (RESIST FINGERPRINTING) RFP covers a wide range of ongoing fingerprinting solutions. It is an all-or-nothing buy in: you cannot pick and choose what parts you want [WARNING] DO NOT USE extensions to alter RFP protected metrics 418986 - limit window.screen & CSS media queries (FF41) [TEST] https://arkenfox.github.io/TZP/tzp.html#screen 1281949 - spoof screen orientation (FF50) 1330890 - spoof timezone as UTC0 (FF55) 1360039 - spoof navigator.hardwareConcurrency as 2 (FF55) 1217238 - reduce precision of time exposed by javascript (FF55) FF56 1369303 - spoof/disable performance API 1333651 - spoof User Agent & Navigator API JS: the version is spoofed as ESR, and the OS as Windows 10, OS 10.15, Android 10, or Linux HTTP Headers: spoofed as Windows or Android 1369319 - disable device sensor API 1369357 - disable site specific zoom 1337161 - hide gamepads from content 1372072 - spoof network information API as "unknown" when dom.netinfo.enabled = true 1333641 - reduce fingerprinting in WebSpeech API FF57 1369309 - spoof media statistics 1382499 - reduce screen co-ordinate fingerprinting in Touch API 1217290 & 1409677 - enable some fingerprinting resistance for WebGL 1382545 - reduce fingerprinting in Animation API 1354633 - limit MediaError.message to a whitelist FF58-90 967895 - spoof canvas and enable site permission prompt (FF58) 1372073 - spoof/block fingerprinting in MediaDevices API (FF59) Spoof: enumerate devices as one "Internal Camera" and one "Internal Microphone" Block: suppresses the ondevicechange event 1039069 - warn when language prefs are not set to "en*" (also see 0210, 0211) (FF59) 1222285 & 1433592 - spoof keyboard events and suppress keyboard modifier events (FF59) Spoofing mimics the content language of the document. Currently it only supports en-US. Modifier events suppressed are SHIFT and both ALT keys. Chrome is not affected. 1337157 - disable WebGL debug renderer info (FF60) 1459089 - disable OS locale in HTTP Accept-Language headers (ANDROID) (FF62) 1479239 - return "no-preference" with prefers-reduced-motion (FF63) 1363508 - spoof/suppress Pointer Events (FF64) 1492766 - spoof pointerEvent.pointerid (FF65) 1485266 - disable exposure of system colors to CSS or canvas (FF67) 1494034 - return "light" with prefers-color-scheme (FF67) 1564422 - spoof audioContext outputLatency (FF70) 1595823 - return audioContext sampleRate as 44100 (FF72) 1607316 - spoof pointer as coarse and hover as none (ANDROID) (FF74) 1621433 - randomize canvas (previously FF58+ returned an all-white canvas) (FF78) 1653987 - limit font visibility to bundled and "Base Fonts" (Windows, Mac, some Linux) (FF80) 1461454 - spoof smooth=true and powerEfficient=false for supported media in MediaCapabilities (FF82) FF91+ 531915 - use fdlibm's sin, cos and tan in jsmath (FF93, ESR91.1) ***/ user_pref("_user.js.parrot", "4500 syntax error: the parrot's popped 'is clogs"); /* 4501: enable privacy.resistFingerprinting [FF41+] * [SETUP-WEB] RFP can cause some website breakage: mainly canvas, use a site exception via the urlbar * RFP also has a few side effects: mainly timezone is UTC0, and websites will prefer light theme * [1] https://bugzilla.mozilla.org/418986 ***/ user_pref("privacy.resistFingerprinting", true); /* 4502: set new window sizes to round to hundreds [FF55+] [SETUP-CHROME] * Width will round down to multiples of 200s and height to 100s, to fit your screen. * The max values are a starting point to round from if you want some control * [1] https://bugzilla.mozilla.org/1330882 ***/ // user_pref("privacy.window.maxInnerWidth", 1000); // user_pref("privacy.window.maxInnerHeight", 1000); /* 4503: disable mozAddonManager Web API [FF57+] * [NOTE] To allow extensions to work on AMO, you also need 2662 * [1] https://bugzilla.mozilla.org/buglist.cgi?bug_id=1384330,1406795,1415644,1453988 ***/ user_pref("privacy.resistFingerprinting.block_mozAddonManager", true); // [HIDDEN PREF] /* 4504: enable RFP letterboxing [FF67+] * Dynamically resizes the inner window by applying margins in stepped ranges [2] * If you use the dimension pref, then it will only apply those resolutions. * The format is "width1xheight1, width2xheight2, ..." (e.g. "800x600, 1000x1000") * [SETUP-WEB] This is independent of RFP (4501). If you're not using RFP, or you are but * dislike the margins, then flip this pref, keeping in mind that it is effectively fingerprintable * [WARNING] DO NOT USE: the dimension pref is only meant for testing * [1] https://bugzilla.mozilla.org/1407366 * [2] https://hg.mozilla.org/mozilla-central/rev/6d2d7856e468#l2.32 ***/ user_pref("privacy.resistFingerprinting.letterboxing", true); // [HIDDEN PREF] // user_pref("privacy.resistFingerprinting.letterboxing.dimensions", ""); // [HIDDEN PREF] /* 4505: experimental RFP [FF91+] * [WARNING] DO NOT USE unless testing, see [1] comment 12 * [1] https://bugzilla.mozilla.org/1635603 ***/ // user_pref("privacy.resistFingerprinting.exemptedDomains", "*.example.invalid"); // user_pref("privacy.resistFingerprinting.testGranularityMask", 0); /* 4506: set RFP's font visibility level (1402) [FF94+] ***/ // user_pref("layout.css.font-visibility.resistFingerprinting", 1); /* 4507: disable showing about:blank as soon as possible during startup [FF60+] * When default true this no longer masks the RFP chrome resizing activity * [1] https://bugzilla.mozilla.org/1448423 ***/ user_pref("browser.startup.blankWindow", false); /* 4510: disable using system colors * [SETTING] General>Language and Appearance>Fonts and Colors>Colors>Use system colors ***/ user_pref("browser.display.use_system_colors", false); // [DEFAULT false NON-WINDOWS] /* 4511: enforce non-native widget theme * Security: removes/reduces system API calls, e.g. win32k API [1] * Fingerprinting: provides a uniform look and feel across platforms [2] * [1] https://bugzilla.mozilla.org/1381938 * [2] https://bugzilla.mozilla.org/1411425 ***/ user_pref("widget.non-native-theme.enabled", true); // [DEFAULT: true] /* 4512: enforce links targeting new windows to open in a new tab instead * 1=most recent window or tab, 2=new window, 3=new tab * Stops malicious window sizes and some screen resolution leaks. * You can still right-click a link and open in a new window * [SETTING] General>Tabs>Open links in tabs instead of new windows * [TEST] https://arkenfox.github.io/TZP/tzp.html#screen * [1] https://gitlab.torproject.org/tpo/applications/tor-browser/-/issues/9881 ***/ user_pref("browser.link.open_newwindow", 3); // [DEFAULT: 3] /* 4513: set all open window methods to abide by "browser.link.open_newwindow" (4512) * [1] https://searchfox.org/mozilla-central/source/dom/tests/browser/browser_test_new_window_from_content.js ***/ user_pref("browser.link.open_newwindow.restriction", 0); /* 4520: disable WebGL (Web Graphics Library) * [SETUP-WEB] If you need it then enable it. RFP still randomizes canvas for naive scripts ***/ user_pref("webgl.disabled", true); /*** [SECTION 5000]: OPTIONAL OPSEC Disk avoidance, application data isolation, eyeballs... ***/ user_pref("_user.js.parrot", "5000 syntax error: the parrot's taken 'is last bow"); /* 5001: start Firefox in PB (Private Browsing) mode * [NOTE] In this mode all windows are "private windows" and the PB mode icon is not displayed * [NOTE] The P in PB mode can be misleading: it means no "persistent" disk state such as history, * caches, searches, cookies, localStorage, IndexedDB etc (which you can achieve in normal mode). * In fact, PB mode limits or removes the ability to control some of these, and you need to quit * Firefox to clear them. PB is best used as a one off window (Menu>New Private Window) to provide * a temporary self-contained new session. Close all Private Windows to clear the PB mode session. * [SETTING] Privacy & Security>History>Custom Settings>Always use private browsing mode * [1] https://wiki.mozilla.org/Private_Browsing * [2] https://support.mozilla.org/kb/common-myths-about-private-browsing ***/ // user_pref("browser.privatebrowsing.autostart", true); /* 5002: disable memory cache * capacity: -1=determine dynamically (default), 0=none, n=memory capacity in kibibytes ***/ // user_pref("browser.cache.memory.enable", false); // user_pref("browser.cache.memory.capacity", 0); /* 5003: disable saving passwords * [NOTE] This does not clear any passwords already saved * [SETTING] Privacy & Security>Logins and Passwords>Ask to save logins and passwords for websites ***/ // user_pref("signon.rememberSignons", false); /* 5004: disable permissions manager from writing to disk [FF41+] [RESTART] * [NOTE] This means any permission changes are session only * [1] https://bugzilla.mozilla.org/967812 ***/ // user_pref("permissions.memory_only", true); // [HIDDEN PREF] /* 5005: disable intermediate certificate caching [FF41+] [RESTART] * [NOTE] This affects login/cert/key dbs. The effect is all credentials are session-only. * Saved logins and passwords are not available. Reset the pref and restart to return them ***/ // user_pref("security.nocertdb", true); // [HIDDEN PREF] /* 5006: disable favicons in history and bookmarks * [NOTE] Stored as data blobs in favicons.sqlite, these don't reveal anything that your * actual history (and bookmarks) already do. Your history is more detailed, so * control that instead; e.g. disable history, clear history on exit, use PB mode * [NOTE] favicons.sqlite is sanitized on Firefox close ***/ // user_pref("browser.chrome.site_icons", false); /* 5007: exclude "Undo Closed Tabs" in Session Restore ***/ // user_pref("browser.sessionstore.max_tabs_undo", 0); /* 5008: disable resuming session from crash ***/ // user_pref("browser.sessionstore.resume_from_crash", false); /* 5009: disable "open with" in download dialog [FF50+] * Application data isolation [1] * [1] https://bugzilla.mozilla.org/1281959 ***/ // user_pref("browser.download.forbid_open_with", true); /* 5010: disable location bar suggestion types * [SETTING] Privacy & Security>Address Bar>When using the address bar, suggest ***/ // user_pref("browser.urlbar.suggest.history", false); // user_pref("browser.urlbar.suggest.bookmark", false); // user_pref("browser.urlbar.suggest.openpage", false); // user_pref("browser.urlbar.suggest.topsites", false); // [FF78+] /* 5011: disable location bar dropdown * This value controls the total number of entries to appear in the location bar dropdown ***/ // user_pref("browser.urlbar.maxRichResults", 0); /* 5012: disable location bar autofill * [1] https://support.mozilla.org/kb/address-bar-autocomplete-firefox#w_url-autocomplete ***/ // user_pref("browser.urlbar.autoFill", false); /* 5013: disable browsing and download history * [NOTE] We also clear history and downloads on exit (2811) * [SETTING] Privacy & Security>History>Custom Settings>Remember browsing and download history ***/ // user_pref("places.history.enabled", false); /* 5014: disable Windows jumplist [WINDOWS] ***/ // user_pref("browser.taskbar.lists.enabled", false); // user_pref("browser.taskbar.lists.frequent.enabled", false); // user_pref("browser.taskbar.lists.recent.enabled", false); // user_pref("browser.taskbar.lists.tasks.enabled", false); /* 5015: disable Windows taskbar preview [WINDOWS] ***/ // user_pref("browser.taskbar.previews.enable", false); // [DEFAULT: false] /* 5016: discourage downloading to desktop * 0=desktop, 1=downloads (default), 2=last used * [SETTING] To set your default "downloads": General>Downloads>Save files to ***/ // user_pref("browser.download.folderList", 2); /*** [SECTION 5500]: OPTIONAL HARDENING Not recommended. Keep in mind that these can cause breakage and performance issues, are mostly fingerpintable, and the threat model is practically zero ***/ user_pref("_user.js.parrot", "5500 syntax error: this is an ex-parrot!"); /* 5501: disable MathML (Mathematical Markup Language) [FF51+] * [1] https://cve.mitre.org/cgi-bin/cvekey.cgi?keyword=mathml ***/ // user_pref("mathml.disabled", true); // 1173199 /* 5502: disable in-content SVG (Scalable Vector Graphics) [FF53+] * [1] https://cve.mitre.org/cgi-bin/cvekey.cgi?keyword=firefox+svg ***/ // user_pref("svg.disabled", true); // 1216893 /* 5503: disable graphite * [1] https://cve.mitre.org/cgi-bin/cvekey.cgi?keyword=firefox+graphite * [2] https://en.wikipedia.org/wiki/Graphite_(SIL) ***/ // user_pref("gfx.font_rendering.graphite.enabled", false); /* 5504: disable asm.js [FF22+] * [1] http://asmjs.org/ * [2] https://cve.mitre.org/cgi-bin/cvekey.cgi?keyword=asm.js * [3] https://rh0dev.github.io/blog/2017/the-return-of-the-jit/ ***/ // user_pref("javascript.options.asmjs", false); /* 5505: disable Ion and baseline JIT to harden against JS exploits * [NOTE] In FF75+, when **both** Ion and JIT are disabled, **and** the new * hidden pref is enabled, then Ion can still be used by extensions (1599226) * [1] https://cve.mitre.org/cgi-bin/cvekey.cgi?keyword=firefox+jit ***/ // user_pref("javascript.options.ion", false); // user_pref("javascript.options.baselinejit", false); // user_pref("javascript.options.jit_trustedprincipals", true); // [FF75+] [HIDDEN PREF] /* 5506: disable WebAssembly [FF52+] * Vulnerabilities [1] have increasingly been found, including those known and fixed * in native programs years ago [2]. WASM has powerful low-level access, making * certain attacks (brute-force) and vulnerabilities more possible * [STATS] ~0.2% of websites, about half of which are for crytopmining / malvertising [2][3] * [1] https://cve.mitre.org/cgi-bin/cvekey.cgi?keyword=wasm * [2] https://spectrum.ieee.org/tech-talk/telecom/security/more-worries-over-the-security-of-web-assembly * [3] https://www.zdnet.com/article/half-of-the-websites-using-webassembly-use-it-for-malicious-purposes ***/ // user_pref("javascript.options.wasm", false); /*** [SECTION 6000]: DON'T TOUCH ***/ user_pref("_user.js.parrot", "6000 syntax error: the parrot's 'istory!"); /* 6001: enforce Firefox blocklist * [WHY] It includes updates for "revoked certificates" * [1] https://blog.mozilla.org/security/2015/03/03/revoking-intermediate-certificates-introducing-onecrl/ ***/ user_pref("extensions.blocklist.enabled", true); // [DEFAULT: true] /* 6002: enforce no referer spoofing * [WHY] Spoofing can affect CSRF (Cross-Site Request Forgery) protections ***/ user_pref("network.http.referer.spoofSource", false); // [DEFAULT: false] /* 6003: enforce CSP (Content Security Policy) * [1] https://developer.mozilla.org/docs/Web/HTTP/CSP ***/ user_pref("security.csp.enable", true); // [DEFAULT: true] /* 6004: enforce a security delay on some confirmation dialogs such as install, open/save * [1] https://www.squarefree.com/2004/07/01/race-conditions-in-security-dialogs/ ***/ user_pref("security.dialog_enable_delay", 1000); // [DEFAULT: 1000] /* 6005: enforce window.opener protection [FF65+] * Makes rel=noopener implicit for target=_blank in anchor and area elements when no rel attribute is set ***/ user_pref("dom.targetBlankNoOpener.enabled", true); // [DEFAULT: true] /* 6006: enforce "window.name" protection [FF82+] * If a new page from another domain is loaded into a tab, then window.name is set to an empty string. The original * string is restored if the tab reverts back to the original page. This change prevents some cross-site attacks * [TEST] https://arkenfox.github.io/TZP/tests/windownamea.html ***/ user_pref("privacy.window.name.update.enabled", true); // [DEFAULT: true] /* 6050: prefsCleaner: reset previously active items removed from arkenfox in 79-91 ***/ // user_pref("browser.newtabpage.activity-stream.asrouter.providers.snippets", ""); // user_pref("browser.send_pings.require_same_host", ""); // user_pref("dom.allow_cut_copy", ""); // user_pref("dom.vibrator.enabled", ""); // user_pref("media.getusermedia.audiocapture.enabled", ""); // user_pref("media.getusermedia.browser.enabled", ""); // user_pref("media.getusermedia.screensharing.enabled", ""); // user_pref("media.gmp-widevinecdm.visible", ""); // user_pref("network.http.redirection-limit", ""); // user_pref("privacy.partition.network_state", ""); // user_pref("security.insecure_connection_icon.enabled", ""); // [DEFAULT: true FF70+] // user_pref("security.mixed_content.block_active_content", ""); // [DEFAULT: true since at least FF60] // user_pref("security.ssl.enable_ocsp_stapling", ""); // [DEFAULT: true FF26+] // user_pref("webgl.disable-fail-if-major-performance-caveat", ""); // [DEFAULT: true FF86+] // user_pref("webgl.enable-webgl2", ""); // user_pref("webgl.min_capability_mode", ""); /*** [SECTION 7000]: DON'T BOTHER ***/ user_pref("_user.js.parrot", "7000 syntax error: the parrot's pushing up daisies!"); /* 7001: disable APIs * Location-Aware Browsing, Full Screen, offline cache (appCache), Virtual Reality * [WHY] The API state is easily fingerprintable. Geo and VR are behind prompts (7002). * appCache storage capability was removed in FF90. Full screen requires user interaction ***/ // user_pref("geo.enabled", false); // user_pref("full-screen-api.enabled", false); // user_pref("browser.cache.offline.enable", false); // user_pref("dom.vr.enabled", false); /* 7002: set default permissions * Location, Camera, Microphone, Notifications [FF58+] Virtual Reality [FF73+] * 0=always ask (default), 1=allow, 2=block * [WHY] These are fingerprintable via Permissions API, except VR. Just add site * exceptions as allow/block for frequently visited/annoying sites: i.e. not global * [SETTING] to add site exceptions: Ctrl+I>Permissions> * [SETTING] to manage site exceptions: Options>Privacy & Security>Permissions>Settings ***/ // user_pref("permissions.default.geo", 0); // user_pref("permissions.default.camera", 0); // user_pref("permissions.default.microphone", 0); // user_pref("permissions.default.desktop-notification", 0); // user_pref("permissions.default.xr", 0); // Virtual Reality /* 7003: disable non-modern cipher suites [1] * [WHY] Passive fingerprinting. Minimal/non-existent threat of downgrade attacks * [1] https://browserleaks.com/ssl ***/ // user_pref("security.ssl3.ecdhe_ecdsa_aes_256_sha", false); // user_pref("security.ssl3.ecdhe_ecdsa_aes_128_sha", false); // user_pref("security.ssl3.ecdhe_rsa_aes_128_sha", false); // user_pref("security.ssl3.ecdhe_rsa_aes_256_sha", false); // user_pref("security.ssl3.rsa_aes_128_gcm_sha256", false); // no PFS // user_pref("security.ssl3.rsa_aes_256_gcm_sha384", false); // no PFS // user_pref("security.ssl3.rsa_aes_128_sha", false); // no PFS // user_pref("security.ssl3.rsa_aes_256_sha", false); // no PFS /* 7004: control TLS versions * [WHY] Passive fingerprinting. Downgrades are still possible: behind user interaction ***/ // user_pref("security.tls.version.min", 3); // [DEFAULT: 3] // user_pref("security.tls.version.max", 4); /* 7005: disable SSL session IDs [FF36+] * [WHY] Passive fingerprinting and perf costs. These are session-only and isolated * with network partitioning (FF85+) or when using FPI and/or containers ***/ // user_pref("security.ssl.disable_session_identifiers", true); // [HIDDEN PREF] /* 7006: onions * [WHY] Firefox doesn't support hidden services. Use Tor Browser ***/ // user_pref("dom.securecontext.whitelist_onions", true); // 1382359 // user_pref("network.http.referer.hideOnionSource", true); // 1305144 /* 7007: referers * [WHY] Only cross-origin referers (1600s) need control ***/ // user_pref("network.http.sendRefererHeader", 2); // user_pref("network.http.referer.trimmingPolicy", 0); /* 7008: set the default Referrer Policy [FF59+] * 0=no-referer, 1=same-origin, 2=strict-origin-when-cross-origin, 3=no-referrer-when-downgrade * [WHY] Defaults are fine. They can be overridden by a site-controlled Referrer Policy ***/ // user_pref("network.http.referer.defaultPolicy", 2); // [DEFAULT: 2] // user_pref("network.http.referer.defaultPolicy.pbmode", 2); // [DEFAULT: 2] /* 7009: disable HTTP2 * [WHY] Passive fingerprinting. ~50% of sites use HTTP2 [1] * [1] https://w3techs.com/technologies/details/ce-http2/all/all ***/ // user_pref("network.http.spdy.enabled", false); // user_pref("network.http.spdy.enabled.deps", false); // user_pref("network.http.spdy.enabled.http2", false); // user_pref("network.http.spdy.websockets", false); // [FF65+] /* 7010: disable HTTP Alternative Services [FF37+] * [WHY] Already isolated by network partitioning (FF85+) or FPI ***/ // user_pref("network.http.altsvc.enabled", false); // user_pref("network.http.altsvc.oe", false); // [DEFAULT: false FF94+] /* 7011: disable website control over browser right-click context menu * [WHY] Just use Shift-Right-Click ***/ // user_pref("dom.event.contextmenu.enabled", false); /* 7012: disable icon fonts (glyphs) and local fallback rendering * [WHY] Breakage, font fallback is equivalency, also RFP * [1] https://bugzilla.mozilla.org/789788 * [2] https://gitlab.torproject.org/legacy/trac/-/issues/8455 ***/ // user_pref("gfx.downloadable_fonts.enabled", false); // [FF41+] // user_pref("gfx.downloadable_fonts.fallback_delay", -1); /* 7013: disable Clipboard API * [WHY] Fingerprintable. Breakage. Cut/copy/paste require user * interaction, and paste is limited to focused editable fields ***/ // user_pref("dom.event.clipboardevents.enabled", false); /* 7014: disable System Add-on updates * [WHY] It can compromise security. System addons ship with prefs, use those ***/ // user_pref("extensions.systemAddon.update.enabled", false); // [FF62+] // user_pref("extensions.systemAddon.update.url", ""); // [FF44+] /*** [SECTION 8000]: DON'T BOTHER: NON-RFP [WHY] They are insufficient to help anti-fingerprinting and do more harm than good [WARNING] DO NOT USE with RFP. RFP already covers these and they can interfere ***/ user_pref("_user.js.parrot", "8000 syntax error: the parrot's crossed the Jordan"); /* 8001: disable APIs ***/ // user_pref("device.sensors.enabled", false); // user_pref("dom.enable_performance", false); // user_pref("dom.enable_resource_timing", false); // user_pref("dom.gamepad.enabled", false); // user_pref("dom.netinfo.enabled", false); // user_pref("dom.webaudio.enabled", false); /* 8002: disable other ***/ // user_pref("browser.display.use_document_fonts", 0); // user_pref("browser.zoom.siteSpecific", false); // user_pref("dom.w3c_touch_events.enabled", 0); // user_pref("media.navigator.enabled", false); // user_pref("media.ondevicechange.enabled", false); // user_pref("media.video_stats.enabled", false); // user_pref("media.webspeech.synth.enabled", false); // user_pref("webgl.enable-debug-renderer-info", false); /* 8003: spoof ***/ // user_pref("dom.maxHardwareConcurrency", 2); // user_pref("font.system.whitelist", ""); // [HIDDEN PREF] // user_pref("general.appname.override", ""); // [HIDDEN PREF] // user_pref("general.appversion.override", ""); // [HIDDEN PREF] // user_pref("general.buildID.override", ""); // [HIDDEN PREF] // user_pref("general.oscpu.override", ""); // [HIDDEN PREF] // user_pref("general.platform.override", ""); // [HIDDEN PREF] // user_pref("general.useragent.override", ""); // [HIDDEN PREF] // user_pref("ui.use_standins_for_native_colors", true); /*** [SECTION 9000]: PERSONAL Non-project related but useful. If any interest you, add them to your overrides ***/ user_pref("_user.js.parrot", "9000 syntax error: the parrot's cashed in 'is chips!"); /* WELCOME & WHAT'S NEW NOTICES ***/ user_pref("browser.startup.homepage_override.mstone", "ignore"); // master switch // user_pref("startup.homepage_welcome_url", ""); // user_pref("startup.homepage_welcome_url.additional", ""); // user_pref("startup.homepage_override_url", ""); // What's New page after updates /* WARNINGS ***/ // user_pref("browser.tabs.warnOnClose", false); // [DEFAULT false FF94+] // user_pref("browser.tabs.warnOnCloseOtherTabs", false); // user_pref("browser.tabs.warnOnOpen", false); // user_pref("browser.warnOnQuitShortcut", false); // [FF94+] // user_pref("full-screen-api.warning.delay", 0); // user_pref("full-screen-api.warning.timeout", 0); /* APPEARANCE ***/ // user_pref("browser.download.autohideButton", false); // [FF57+] // user_pref("ui.systemUsesDarkTheme", 1); // [FF67+] [HIDDEN PREF] // 0=light, 1=dark: with RFP this only affects chrome // user_pref("toolkit.legacyUserProfileCustomizations.stylesheets", true); // [FF68+] allow userChrome/userContent // user_pref("ui.prefersReducedMotion", 1); // disable chrome animations [FF77+] [RESTART] [HIDDEN PREF] // 0=no-preference, 1=reduce: with RFP this only affects chrome /* CONTENT BEHAVIOR ***/ // user_pref("accessibility.typeaheadfind", true); // enable "Find As You Type" // user_pref("clipboard.autocopy", false); // disable autocopy default [LINUX] // user_pref("layout.spellcheckDefault", 2); // 0=none, 1-multi-line, 2=multi-line & single-line /* UX BEHAVIOR ***/ // user_pref("browser.backspace_action", 2); // 0=previous page, 1=scroll up, 2=do nothing // user_pref("browser.quitShortcut.disabled", true); // disable Ctrl-Q quit shortcut [LINUX] [MAC] [FF87+] // user_pref("browser.tabs.closeWindowWithLastTab", false); // user_pref("browser.tabs.loadBookmarksInTabs", true); // open bookmarks in a new tab [FF57+] // user_pref("browser.urlbar.decodeURLsOnCopy", true); // see bugzilla 1320061 [FF53+] // user_pref("general.autoScroll", false); // middle-click enabling auto-scrolling [DEFAULT: false on Linux] // user_pref("ui.key.menuAccessKey", 0); // disable alt key toggling the menu bar [RESTART] // user_pref("view_source.tab", false); // view "page/selection source" in a new window [FF68+, FF59 and under] /* UX FEATURES ***/ user_pref("browser.messaging-system.whatsNewPanel.enabled", false); // What's New toolbar icon [FF69+] // user_pref("extensions.pocket.enabled", false); // Pocket Account [FF46+] // user_pref("extensions.screenshots.disabled", true); // [FF55+] // user_pref("identity.fxaccounts.enabled", false); // Firefox Accounts & Sync [FF60+] [RESTART] // user_pref("reader.parse-on-load.enabled", false); // Reader View /* OTHER ***/ // user_pref("browser.bookmarks.max_backups", 2); user_pref("browser.newtabpage.activity-stream.asrouter.userprefs.cfr.addons", false); // disable CFR [FF67+] // [SETTING] General>Browsing>Recommend extensions as you browse user_pref("browser.newtabpage.activity-stream.asrouter.userprefs.cfr.features", false); // disable CFR [FF67+] // [SETTING] General>Browsing>Recommend features as you browse // user_pref("network.manage-offline-status", false); // see bugzilla 620472 // user_pref("xpinstall.signatures.required", false); // enforced extension signing (Nightly/ESR) /*** [SECTION 9999]: DEPRECATED / REMOVED / LEGACY / RENAMED Documentation denoted as [-]. Items deprecated in FF78 or earlier have been archived at [1] [1] https://github.com/arkenfox/user.js/issues/123 ***/ user_pref("_user.js.parrot", "9999 syntax error: the parrot's shuffled off 'is mortal coil!"); /* ESR91.x still uses all the following prefs // [NOTE] replace the * with a slash in the line above to re-enable them // FF93 // 7003: disable non-modern cipher suites // [-] https://bugzilla.mozilla.org/1724072 // user_pref("security.ssl3.rsa_des_ede3_sha", false); // 3DES // FF94 // 1402: limit font visibility (Windows, Mac, some Linux) [FF79+] - replaced by new 1402 // [-] https://bugzilla.mozilla.org/1715507 // user_pref("layout.css.font-visibility.level", 1); // ***/ /* ESR78.x still uses all the following prefs // [NOTE] replace the * with a slash in the line above to re-enable them // FF79 // 0212: enforce fallback text encoding to match en-US // When the content or server doesn't declare a charset the browser will // fallback to the "Current locale" based on your application language // [TEST] https://hsivonen.com/test/moz/check-charset.htm // [1] https://gitlab.torproject.org/tpo/applications/tor-browser/-/issues/20025 // [-] https://bugzilla.mozilla.org/1603712 user_pref("intl.charset.fallback.override", "windows-1252"); // FF82 // 0206: disable geographically specific results/search engines e.g. "browser.search.*.US" // i.e. ignore all of Mozilla's various search engines in multiple locales // [-] https://bugzilla.mozilla.org/1619926 user_pref("browser.search.geoSpecificDefaults", false); user_pref("browser.search.geoSpecificDefaults.url", ""); // FF86 // 1205: disable SSL Error Reporting // [1] https://firefox-source-docs.mozilla.org/main/65.0/browser/base/sslerrorreport/preferences.html // [-] https://bugzilla.mozilla.org/1681839 user_pref("security.ssl.errorReporting.automatic", false); user_pref("security.ssl.errorReporting.enabled", false); user_pref("security.ssl.errorReporting.url", ""); // 2653: disable hiding mime types (Options>General>Applications) not associated with a plugin // [-] https://bugzilla.mozilla.org/1581678 user_pref("browser.download.hide_plugins_without_extensions", false); // FF87 // 0105d: disable Activity Stream recent Highlights in the Library [FF57+] // [-] https://bugzilla.mozilla.org/1689405 // user_pref("browser.library.activity-stream.enabled", false); // 8002: disable PointerEvents // [1] https://developer.mozilla.org/docs/Web/API/PointerEvent // [-] https://bugzilla.mozilla.org/1688105 // user_pref("dom.w3c_pointer_events.enabled", false); // FF89 // 0309: disable sending Flash crash reports // [-] https://bugzilla.mozilla.org/1682030 [underlying NPAPI code removed] user_pref("dom.ipc.plugins.flash.subprocess.crashreporter.enabled", false); // 0310: disable sending the URL of the website where a plugin crashed // [-] https://bugzilla.mozilla.org/1682030 [underlying NPAPI code removed] user_pref("dom.ipc.plugins.reportCrashURL", false); // 1243: block unencrypted requests from Flash on encrypted pages to mitigate MitM attacks [FF59+] // [1] https://bugzilla.mozilla.org/1190623 // [-] https://bugzilla.mozilla.org/1682030 [underlying NPAPI code removed] user_pref("security.mixed_content.block_object_subrequest", true); // 1803: disable Flash plugin // 0=deactivated, 1=ask, 2=enabled // ESR52.x is the last branch to fully support NPAPI, FF52+ stable only supports Flash // [NOTE] You can still override individual sites via site permissions // [-] https://bugzilla.mozilla.org/1682030 [underlying NPAPI code removed] user_pref("plugin.state.flash", 0); // [DEFAULT: 1] // FF90 // 0708: disable FTP [FF60+] // [-] https://bugzilla.mozilla.org/1574475 // user_pref("network.ftp.enabled", false); // [DEFAULT: false FF88+] // 7001: enforce no offline cache storage (appCache) [FF71+] // [-] https://bugzilla.mozilla.org/1694662 user_pref("browser.cache.offline.storage.enable", false); // [DEFAULT: false FF84+] // ***/ /* END: internal custom pref to test for syntax errors ***/ user_pref("_user.js.parrot", "SUCCESS: No no he's not dead, he's, he's restin'!");