mirror of
https://github.com/Kicksecure/security-misc.git
synced 2024-12-29 11:16:12 -05:00
155 lines
4.7 KiB
Plaintext
155 lines
4.7 KiB
Plaintext
## Copyright (C) 2019 - 2023 ENCRYPTED SUPPORT LP <adrelanos@whonix.org>
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## See the file COPYING for copying conditions.
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## Disables coredumps. This setting may be overwritten by systemd so this may not be useful.
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## security-misc also disables coredumps in other ways.
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kernel.core_pattern=|/bin/false
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## Restricts the kernel log to root only.
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kernel.dmesg_restrict=1
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## Don't allow writes to files that we don't own
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## in world writable sticky directories, unless
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## they are owned by the owner of the directory.
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fs.protected_fifos=2
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fs.protected_regular=2
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## Only allow symlinks to be followed when outside of
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## a world-writable sticky directory, or when the owner
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## of the symlink and follower match, or when the directory
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## owner matches the symlink's owner.
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##
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## Prevent hardlinks from being created by users that do not
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## have read/write access to the source file.
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##
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## These prevent many TOCTOU races.
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fs.protected_symlinks=1
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fs.protected_hardlinks=1
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## Hardens the BPF JIT compiler and restricts it to root.
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kernel.unprivileged_bpf_disabled=1
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net.core.bpf_jit_harden=2
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## Hides kernel addresses in various files in /proc.
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## Kernel addresses can be very useful in certain exploits.
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##
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## https://kernsec.org/wiki/index.php/Bug_Classes/Kernel_pointer_leak
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kernel.kptr_restrict=2
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## Improves ASLR effectiveness for mmap.
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vm.mmap_rnd_bits=32
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vm.mmap_rnd_compat_bits=16
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## Restricts the use of ptrace to root. This might break some programs running under WINE.
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## A workaround for WINE would be to give the wineserver and wine-preloader ptrace capabilities. This can be done by running:
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##
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## sudo apt-get install libcap2-bin
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## sudo setcap cap_sys_ptrace=eip /usr/bin/wineserver
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## sudo setcap cap_sys_ptrace=eip /usr/bin/wine-preloader
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kernel.yama.ptrace_scope=2
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## Prevent setuid processes from creating coredumps.
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fs.suid_dumpable=0
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## Randomize the addresses for mmap base, heap, stack, and VDSO pages
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kernel.randomize_va_space=2
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#### meta start
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#### project Kicksecure
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#### category networking and security
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#### description
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## TCP/IP stack hardening
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## Protects against time-wait assassination.
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## It drops RST packets for sockets in the time-wait state.
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net.ipv4.tcp_rfc1337=1
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## Disables ICMP redirect acceptance.
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net.ipv4.conf.all.accept_redirects=0
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net.ipv4.conf.default.accept_redirects=0
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net.ipv4.conf.all.secure_redirects=0
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net.ipv4.conf.default.secure_redirects=0
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net.ipv6.conf.all.accept_redirects=0
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net.ipv6.conf.default.accept_redirects=0
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## Disables ICMP redirect sending.
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net.ipv4.conf.all.send_redirects=0
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net.ipv4.conf.default.send_redirects=0
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## Ignores ICMP requests.
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net.ipv4.icmp_echo_ignore_all=1
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net.ipv6.icmp.echo_ignore_all=1
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## Ignores bogus ICMP error responses
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net.ipv4.icmp_ignore_bogus_error_responses=1
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## Enables TCP syncookies.
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net.ipv4.tcp_syncookies=1
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## Disable source routing.
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net.ipv4.conf.all.accept_source_route=0
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net.ipv4.conf.default.accept_source_route=0
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net.ipv6.conf.all.accept_source_route=0
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net.ipv6.conf.default.accept_source_route=0
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## Enable reverse path filtering to prevent IP spoofing and
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## mitigate vulnerabilities such as CVE-2019-14899.
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## https://forums.whonix.org/t/enable-reverse-path-filtering/8594
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net.ipv4.conf.default.rp_filter=1
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net.ipv4.conf.all.rp_filter=1
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#### meta end
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## Previously disabled SACK, DSACK, and FACK.
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## https://forums.whonix.org/t/disabling-tcp-sack-dsack-fack/8109
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#net.ipv4.tcp_sack=0
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#net.ipv4.tcp_dsack=0
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#net.ipv4.tcp_fack=0
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#### meta start
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#### project Kicksecure
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#### category networking and security
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#### description
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## disable IPv4 TCP Timestamps
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net.ipv4.tcp_timestamps=0
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#### meta end
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## Only allow the SysRq key to be used for shutdowns and the
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## Secure Attention Key (SAK).
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##
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## https://forums.whonix.org/t/sysrq-magic-sysrq-key/8079/
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kernel.sysrq=132
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## Restrict loading TTY line disciplines to CAP_SYS_MODULE to prevent
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## unprivileged attackers from loading vulnerable line disciplines
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## with the TIOCSETD ioctl which has been used in exploits before
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## such as https://a13xp0p0v.github.io/2017/03/24/CVE-2017-2636.html
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##
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## https://lkml.org/lkml/2019/4/15/890
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dev.tty.ldisc_autoload=0
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## Restrict the userfaultfd() syscall to root as it can make heap sprays
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## easier.
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##
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## https://duasynt.com/blog/linux-kernel-heap-spray
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vm.unprivileged_userfaultfd=0
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## Let the kernel only swap if it is absolutely necessary.
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## Better not be set to zero:
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## - https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Performance_Tuning_Guide/s-memory-tunables.html
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## - https://en.wikipedia.org/wiki/Swappiness
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vm.swappiness=1
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## Disallow kernel profiling by users without CAP_SYS_ADMIN
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## https://www.kernel.org/doc/Documentation/sysctl/kernel.txt
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kernel.perf_event_paranoid=3
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# Do not accept router advertisments
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net.ipv6.conf.all.accept_ra=0
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net.ipv6.conf.default.accept_ra=0
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