Skip to content

Instantly share code, notes, and snippets.

@andruby
Forked from koelling/gist:ef9b2b9d0be6d6dbab63
Last active August 29, 2015 14:14
Show Gist options
  • Save andruby/9f8f3fd79fd2b8aaaa69 to your computer and use it in GitHub Desktop.
Save andruby/9f8f3fd79fd2b8aaaa69 to your computer and use it in GitHub Desktop.
#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);
}
/* from http://www.openwall.com/lists/oss-security/2015/01/27/9 */
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment