find-libc-in-memory-of-processes-run-as-root.py

import os, glob, re
def main():
    p = re.compile('^([0-9a-f]+-[0-9a-f]+)\s[a-z\-]{4}\s[0-9a-f]{8}\s[a-z0-9]{2}\:[a-z0-9]{2}\s[0-9]+\s+(.*)$')
    smaps = glob.glob('/proc/[0-9]*/smaps')
    for smap in smaps:
        lines = open(smap).readlines()
        for line in lines:
            m = p.match(line)
            if m and 'libc' in line:
                name = open(smap.replace('smaps','status')).readlines()[0]
                print 'Found potential match at memory', m.group(1), name.strip(), m.group(2).strip()
                     
if __name__ == '__main__':
    main()

qualys-cve-2015-0235.c

cat > GHOST.c << EOF
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>

#define CANARY "in_the_coal_mine"

struct {
  char buffer[1024];
  char canary[sizeof(CANARY)];
} temp = { "buffer", CANARY };

int main(void) {
  struct hostent resbuf;
  struct hostent *result;
  int herrno;
  int retval;

  /*** strlen (name) = size_needed - sizeof (*host_addr) - sizeof (*h_addr_ptrs) - 1; ***/
  size_t len = sizeof(temp.buffer) - 16*sizeof(unsigned char) - 2*sizeof(char *) - 1;
  char name[sizeof(temp.buffer)];
  memset(name, '0', len);
  name[len] = '\0';

  retval = gethostbyname_r(name, &resbuf, temp.buffer, sizeof(temp.buffer), &result, &herrno);

  if (strcmp(temp.canary, CANARY) != 0) {
    puts("vulnerable");
    exit(EXIT_SUCCESS);
  }
  if (retval == ERANGE) {
    puts("not vulnerable");
    exit(EXIT_SUCCESS);
  }
  puts("should not happen");
  exit(EXIT_FAILURE);
}
EOF