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Re: Microsoft Help (WINHLP32.EXE) - Multiple Remote Code Execution and Denial Of Service Vulnerabilities
From: Reversemode <advisories () reversemode com>
Date: Sat, 12 Aug 2006 21:54:41 +0200
Hi, Nobody should open an untrusted .HLP file. An HLP file is the most similar to an executable but not being one, mainly due to its powerful scripting language. One of the documented macros documented and supported by this format is "RegisterRoutine". Using this macro we can reference any Export of any Dll. Example: [CONFIG] RegisterRoutine("Kernel32.dll", "Beep", "UU") so the function can be used as a Macro within the WinHelp project {\uldb Do Beep}{\v !Beep(750, 5000)} The user won´t see any warning previously the execution of this macro. I wonder why Microsoft and a lot of vendors are still using this old-and-dangerous format for providing documentation. Greets, Rubén. Benjamin Tobias Franz wrote:
Microsoft Help (WINHLP32.EXE) - Multiple Remote Code Execution and Denial Of Service Vulnerabilities ... discovered by Benjamin Tobias Franz Affected Vendor: Microsoft Affected Product: Microsoft Windows - Microsoft Help (WINHLP32.EXE) Description: Multiple remote code execution and denial of service vulnerabilities exists in Microsoft Help (WINHLP32.EXE) because of the way that it handles Microsoft Windows Help files (*.HLP). An attacker could exploit this by placing a specially crafted help file on a webpage, or by sending the file as an attachment in an e-mail. The exploit is triggered by viewing the specially crafted help file. No user interaction is required. An attacker who successfully exploited this vulnerability could take complete control of the affected system. Workaround: Do not open any HLP file from untrusted sources with Microsoft Help. Proof-Of-Concept files (simple demonstration files only): http://hometown.aol.de/qwertzset/BTFs_MSHelp_WINHLP32.EXE_POCFiles.zip Date of discovery: 20. - 22. July 2006 Tested software: Microsoft Help on Windows XP SP2 (WINHLP32.EXE: 5.1.2600.2180 | MSVCRT.DLL: 7.0.2600.2180) Probably all versions of Microsoft Windows are affected by these bugs. Regards, Benjamin Tobias Franz, Germany
Current thread:
- Microsoft Help (WINHLP32.EXE) - Multiple Remote Code Execution and Denial Of Service Vulnerabilities Benjamin Tobias Franz (Aug 12)
- Re: Microsoft Help (WINHLP32.EXE) - Multiple Remote Code Execution and Denial Of Service Vulnerabilities Reversemode (Aug 12)