Description
The MPC::HexToNum function in helpctr.exe in Microsoft Windows Help and Support Center in Windows XP and Windows Server 2003 does not properly handle malformed escape sequences, which allows remote attackers to bypass the trusted documents whitelist (fromHCP option) and execute arbitrary commands via a crafted hcp:// URL, aka "Help Center URL Validation Vulnerability."
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Metasploit 1 module
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Microsoft Help Center XSS and Command Execution
exploit/windows/browser/ms10_042_helpctr_xss_cmd_exec
Exploit-DB 2
- Microsoft Help Center - Cross-Site Scripting / Command Execution (MS10-042) (Metasploit) EDB-16545 · remote · Sep 20, 2010 · verified
- Microsoft Windows Help Centre Handles - Malformed Escape Sequences Incorrectly (MS03-044) EDB-13808 · remote · Jun 10, 2010 · verified
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
References
- VU#578319 third-party-advisory
- 20100609 Microsoft Windows Help Centre Handles Malformed Escape Sequences Incorrectly mailing-list
- ms-win-helpctr-command-execution(59267) vdb-entry
- 20100610 Re: Microsoft Windows Help Centre Handles Malformed Escape Sequences Incorrectly mailing-list
- http://blogs.technet.com/b/srd/archive/2010/06/10/help-and-support-center-vulnerability-full-disclosure-posting.aspx
- 40725 vdb-entry
- 20100609 Microsoft Windows Help Centre Handles Malformed Escape Sequences Incorrectly mailing-list
- 1024084 vdb-entry
- 13808 exploit
- http://blogs.technet.com/b/msrc/archive/2010/06/10/windows-help-vulnerability-disclosure.aspx
- http://www.microsoft.com/technet/security/advisory/2219475.mspx
- TA10-194A third-party-advisory
- oval:org.mitre.oval:def:11733 vdb-entry signature
- ADV-2010-1417 vdb-entry
- MS10-042 vendor-advisory
- 40076 third-party-advisory