Full Disclosure mailing list archives
Re: GAYER THAN AIDS ADVISORY #01: IE 5 remote code execution
From: KF <dotslash () snosoft com>
Date: Sun, 15 Feb 2004 12:58:35 -0500
Man ... those voices in my head... they keep screaming "DMCA"! -KF gta () hush com wrote:
I downloaded the Microsoft source code. Easy enough. It's a lot bigger than Linux, but there were a lot of people mirroring it and so it didn't take long. Anyway, I took a look, and decided that Microsoft is GAYER THAN AIDS. For example, in win2k/private/inet/mshtml/src/site/download/imgbmp.cxx: // Before we read the bits, seek to the correct location in the file while (_bmfh.bfOffBits > (unsigned)cbRead) { BYTE abDummy[1024]; int cbSkip; cbSkip = _bmfh.bfOffBits - cbRead;if (cbSkip > 1024)cbSkip = 1024; if (!Read(abDummy, cbSkip)) goto Cleanup;cbRead += cbSkip;} .. Rrrrriiiiggghhhttt. Way to go, using a signed integer for an offset. Now all we have to do is create a BMP with bfOffBits > 2^31, and we're in. cbSkip goes negative and the Read call clobbers the stack with our data. See attached for proof of concept. index.html has [img src=1.bmp] where 1.bmp contains bfOffBits=0xEEEEEEEE plus 4k of 0x44332211. Bring it up in IE5 (tested successfully on Win98) and get EIP=0x44332211. IE6 is not vulnerable, so I guess I'll get back to work. My Warhol worm will have to wait a bit... .gta PROPS TO the Fort and HAVE IT BE YOU. ------------------------------------------------------------------------ Hello
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Current thread:
- GAYER THAN AIDS ADVISORY #01: IE 5 remote code execution gta (Feb 15)
- Microsoft source code "leak" Exibar (Feb 15)
- Re: Microsoft source code "leak" Joshua Levitsky (Feb 15)
- Re: GAYER THAN AIDS ADVISORY #01: IE 5 remote code execution KF (Feb 15)
- Re: GAYER THAN AIDS ADVISORY #01: IE 5 remote code execution morning_wood (Feb 15)
- Re: GAYER THAN AIDS ADVISORY #01: IE 5 remote code execution KF (Feb 15)
- Re: GAYER THAN AIDS ADVISORY #01: IE 5 remote code execution morning_wood (Feb 15)
- Re: GAYER THAN AIDS ADVISORY #01: IE 5 remote code execution Byron Copeland (Feb 15)
- RE: GAYER THAN AIDS ADVISORY #01: IE 5 remote code execution Aditya, ALD [Aditya Lalit Deshmukh] (Feb 16)
- Re: GAYER THAN AIDS ADVISORY #01: IE 5 remote code execution morning_wood (Feb 17)
- Re: GAYER THAN AIDS ADVISORY #01: IE 5 remote code execution gabriel rosenkoetter (Feb 18)
- Re: Re: GAYER THAN AIDS ADVISORY #01: IE 5 remote code execution Dave Sherohman (Feb 18)
- RE: Re: GAYER THAN AIDS ADVISORY #01: IE 5 remote code execution Steve Wray (Feb 18)
- Re: Re: GAYER THAN AIDS ADVISORY #01: IE 5 remote code execution Tim (Feb 18)
- Re: GAYER THAN AIDS ADVISORY #01: IE 5 remote code execution morning_wood (Feb 15)
- Microsoft source code "leak" Exibar (Feb 15)