Check GHOST vulnerability one-liner with most reliable check script: curl -kL https://gist.githubusercontent.com/adionditsak/975764eba35273856be1/raw/2f9b31e39c22c03d6ef2152f8128165ef7c1aa27/check_ghost.sh | bash

check_ghost.sh

#!/bin/bash

red='\033[0;35m'
NC='\033[0m'

echo "Downloading GHOST check script"
curl -kL https://gist.githubusercontent.com/adionditsak/975764eba35273856be1/raw/e5812798b8dffd139d3be8663a6bedf4eeeeb613/GHOST.c -o GHOST.c
echo "Compiling GHOST check script"
gcc GHOST.c -o GHOST
RESULT=$(./GHOST)
echo -e "${red}${RESULT}${NC}"
echo "Vacuuming..."
rm GHOST.c GHOST
echo "Done"

GHOST.c

#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);
}

output_example.txt

[root@host ~]# curl -kL https://gist.githubusercontent.com/adionditsak/975764eba35273856be1/raw/2f9b31e39c22c03d6ef2152f8128165ef7c1aa27/check_ghost.sh | bash
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
125   377  125   377    0     0   3485      0 --:--:-- --:--:-- --:--:-- 25133
Downloading GHOST check script
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   905  100   905    0     0   6749      0 --:--:-- --:--:-- --:--:-- 56562
Compiling GHOST check script
not vulnerable
Vacuuming...
Done

runthis.sh

curl -kL https://gist.githubusercontent.com/adionditsak/975764eba35273856be1/raw/2f9b31e39c22c03d6ef2152f8128165ef7c1aa27/check_ghost.sh | bash