Buffer Overflow Example

This is an example of a very bad coding practices that introduces a buffer overflow. The purpose of this code is to serve as a demonstration and exercise for The Art of Hacking Series and live training

#include <stdio.h>

void secretFunction()
{
    printf("Omar's Crappy Function\n");
    printf("This is a super secret function!\n");
}

void echo()
{
    char buffer[20];

    printf("Please enter your name:\n");
    scanf("%s", buffer);
    printf("You entered: %s\n", buffer);    
}

int main()
{
    echo();

    return 0;
}

The char buffer[20]; is a really bad idea. The rest will be demonstrated in the course.

You can compile this code or use the already-compiled binary here.

For 32 bit systems you can use gcc as shown below:

gcc vuln.c -o vuln -fno-stack-protector

For 64 bit systems

gcc vuln.c -o vuln -fno-stack-protector -m32

-fno-stack-protector disabled the stack protection. Smashing the stack is now allowed. -m32 made sure that the compiled binary is 32 bit. You may need to install some additional libraries to compile 32 bit binaries on 64 bit machines.

1.5 KiB Raw Blame History

Buffer Overflow Example

1.5 KiB

Raw Blame History