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cassemblygdbbuffer-overflowexploit

Buffer overflow - Program terminated with signal SIGSEGV

I'm learning buffer overflow exploiting. I wrote a vulnerable program like this:

#include <stdio.h>
#include <string.h>

main(int argc, char *argv[])
{
    char buffer[80];
    strcpy(buffer, argv[1]);
    return 1;
}

Very simple program. The idea is to overwrite the return address that's used to return to the libc function start_main. Everything went fine and I used GDB to verify that the return address is overwritten with the right address that points to the shellcode in the memory.

But when I'm suppose to get a shell this appears:

Program received signal SIGSEGV, Segmentation fault. 0xbffff178 in ?? ()

0xbffff178 is the return overwritten return address and it does point to the shellcode I'm pretty sure. Any help?

Solution

  • You probably have a no-execute stack, which prohibits code from being executed from certain address ranges. You need to compile with -z execstack to force the stack to be executable.