Microsoft Ships Urgent Patch for Exploited Windows CLFS Zero-Day

Microsoft Ships Urgent Patch for Exploited Windows CLFS Zero-Day

December 10, 2024 at 03:33PM

Microsoft has issued patches for over 70 security flaws, highlighting an actively exploited zero-day vulnerability in Windows’ Common Log File System (CLFS), CVE-2024-49138. Additionally, a critical LDAP remote code execution issue (CVE-2024-49112) has been flagged, with urgent recommendations for mitigation measures.

### Meeting Takeaways:

1. **Security Patches Released**:
– Microsoft issued patches for over 70 documented security vulnerabilities on December Patch Tuesday.

2. **Critical Vulnerabilities**:
– **CVE-2024-49138**: A zero-day vulnerability in the Windows Common Log File System (CLFS) is actively exploited and has a CVSS severity score of 7.8. It allows attackers to gain SYSTEM privileges via a heap-based buffer overflow, requiring low privileges and no user interaction. Microsoft has not provided indicators of compromise (IOCs) for this vulnerability.

– **CVE-2024-49112**: A critical Windows LDAP remote code execution vulnerability with a CVSS score of 9.8. Microsoft recommends temporarily disconnecting Domain Controllers from the internet to mitigate risks. Successful exploitation could allow unauthenticated attackers to execute arbitrary code.

3. **Additional Vulnerabilities**:
– The patch release also addresses:
– A significant guest-to-host remote code execution flaw in Windows Hyper-V (CVE-2024-49117).
– Multiple critical flaws in Windows Remote Desktop Services.
– Defects in Microsoft Message Queuing (MSMQ) service and a critical remote code execution issue related to Microsoft/Muzic AI project.

4. **Historical Context**:
– Microsoft has patched 1,020 vulnerabilities in 2024 so far and documented at least 27 zero-day attacks in the Windows ecosystem this year.

5. **Future Security Enhancements**:
– Microsoft is planning to implement Hash-based Message Authentication Codes (HMAC) to bolster security against modifications to CLFS log files, particularly in light of past vulnerabilities.

6. **Ongoing Security Trends**:
– Over the past five years, there have been at least 25 vulnerabilities identified in the CLFS, highlighting a persistent target for cyberattacks.

### Action Items:
– Sysadmins should prioritize applying patches related to the critical vulnerabilities, especially CVE-2024-49112 and CVE-2024-49138.
– Consider the temporary disconnection of Domain Controllers from the internet as a precaution.
– Stay updated with Microsoft’s security bulletins and apply all recommended updates promptly.

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