Micropatches Released for Windows MSHTML Platform Spoofing (CVE-2024-38112)

 

July 2024 Windows Updates brought a patch for CVE-2024-38112, a vulnerability in Windows that allows an attacker to create a Windows Internet Shortcut file (extension .url) that will look exactly like a PDF document, while clicking on it opens attacker's web page in Internet Explorer. The problem there is that Internet Explorer, which is still present on Windows computers and integrated into many applications, is easier to exploit as it has no real sandbox.

This issue was reported to Microsoft by Haifei Li with Check Point Research, whose researchers noticed it being used by threat actors. Haifei later wrote an article detailing the vulnerability, demonstrating how a malicious executable could be executed using this trick. In addition, exploitation of the same issue was also detected in the wild by Trend Micro; they, too, reported it to Microsoft.

Microsoft patched this by deleting a small piece of code from ieframe.dll which allowed for Internet Explorer to be launched via a URL file.

Unsupported Windows versions that we have security-adopted were also affected by this issue, so we created a micropatch for them. Our micropatch is logically equivalent to Microsoft's, containing a single JMP instruction to jump over the code that Microsoft removed on supported Windows versions.

Micropatch Availability

Micropatches were written for the following security-adopted versions of Windows with all available Windows Updates installed:

1. Windows 11 v21H2 - fully updated
2. Windows 10 v21H2 - fully updated
3. Windows 10 v21H1 - fully updated
4. Windows 10 v20H2 - fully updated
5. Windows 10 v2004 - fully updated
6. Windows 10 v1909 - fully updated
7. Windows 10 v1809 - fully updated
8. Windows 10 v1803 - fully updated
9. Windows 7 - fully updated with no ESU, ESU 1/2/3
10. Windows Server 2008 R2 - fully updated with no ESU, ESU 1/2/3/4
    

 

Micropatches have already been distributed to, and applied on, all online 0patch Agents in PRO or Enterprise accounts (unless Enterprise group settings prevent that). 

Vulnerabilities like these get discovered on a regular basis, and attackers know about them all. If you're using Windows that aren't receiving official security updates anymore, 0patch will make sure these vulnerabilities won't be exploited on your computers - and you won't even have to know or care about these things.

If you're new to 0patch, create a free account in 0patch Central with a free monthly trial, then install and register 0patch Agent (link in 0patch Central). Everything else will happen automatically. No computer reboot will be needed.

We would like to thank Haifei Li with Check Point Research for sharing their analysis and POC, which made it possible for us to create a micropatch for this issue.

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