Created
January 28, 2015 03:29
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/* See http://yinette.github.io/blog/2015/01/28/ghost-in-the-library/ for more info */ | |
#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); | |
} |
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