CVE-2024-49138: Windows CLFS Driver Heap Buffer Overflow Elevation of Privilege

Automated analysis

Generated by VULONE's analysis model from the NVD record, CISA KEV and EPSS data on 17 September 2026. Confidence: high.

high priorityIt is a locally exploitable kernel privilege escalation with public exploits and active inclusion in CISA KEV, though it requires local access rather than remote reach.

What it is

The Windows Common Log File System (CLFS) driver contains a heap-based buffer overflow that allows a local attacker to elevate privileges. Because CLFS is a core kernel component present across Windows client and server releases, a reliable local exploit gives an attacker full control of the host.

Impact

An attacker who successfully exploits the overflow gains SYSTEM-level privileges, enabling arbitrary code execution in kernel context, persistence, and disabling of security controls.

Attack surface

Reached locally via the CLFS driver interface; the CVSS vector AV:L/PR:L/UI:N indicates a low-privileged local user is required and no user interaction is needed. No remote or network vector is described.

Exploitation

CISA added this to KEV on 2024-12-10 with a remediation due date of 2024-12-31, and public exploit references exist on Packet Storm and Exploit-DB. EPSS is 0.26215 (97.9th percentile), indicating high likelihood of exploitation activity.

What to do

• Apply the Microsoft December 2024 security update for CVE-2024-49138 on all affected Windows client and server versions.
• Prioritize internet-facing and multi-user systems, and complete patching before the CISA KEV due date of 2024-12-31.
• Restrict local logon and interactive access to only trusted users to reduce the low-privileged attack surface.
• Monitor for and block known public exploit tooling tied to this CLFS overflow where feasible.
• If patching cannot be completed, follow vendor mitigations or discontinue use of the affected product per CISA guidance.

Detection

• Monitor for unexpected SYSTEM-level process creation or privilege escalation events originating from non-administrative user sessions.
• Audit CLFS-related driver activity and unusual writes to CLFS log files or base log (.blf) files.
• Correlate local exploit indicators with known public PoC behavior from Exploit-DB and Packet Storm references.
• Alert on suspicious kernel-mode crashes or bugcheck events involving the CLFS driver.

This assessment is produced automatically and is not human-reviewed. Verify against the vendor advisory before acting on it.