Use‑After‑Free in Microsoft Windows CLFS Driver (CVE‑2025‑29824) Enables Local Privilege Escalation
What It Is – The Windows Common Log File System (CLFS) driver contains a use‑after‑free flaw that allows an attacker with a valid account on the host to execute code with SYSTEM privileges.
Exploitability – The vulnerability is publicly disclosed (CVE‑2025‑29824) and a proof‑of‑concept exists; Microsoft has issued a security advisory and a patch. CVSS v3.1 base score 7.8 (High).
Affected Products – Microsoft Windows operating systems that include the CLFS driver (all supported client and server releases as of 2025).
Why It Matters for Trust & Control Assurance
- Vulnerability Management – The flaw tests the control objective of maintaining a robust patch‑management process and timely remediation of high‑severity defects.
- Least‑Privilege Enforcement – Successful exploitation bypasses normal access controls, highlighting the need for continuous monitoring of privileged activity.
- Audit Readiness – Demonstrating that patches are applied and evidence is retained satisfies multiple framework controls (e.g., NIST CSF Identify/Protect, ISO 27001 A.12.6).
Recommended Actions
- Identify all Windows endpoints running the vulnerable CLFS driver.
- Deploy Microsoft’s security update (KB xxxxx) immediately via your patch‑management system.
- Verify remediation with a vulnerability‑scan or endpoint‑detection tool and capture remediation logs as audit evidence.
- Update your vulnerability‑management register and map the fix to the “Patch Management” control objective in your chosen framework.
Source: CISA KEV – CVE‑2025‑29824