CVE-2021-36955

Windows Common Log File System Driver Elevation of Privilege Vulnerability

CVSS 7.8 HIGHEPSS 3.1%● KEV

Vexday Risk Score

71High priority

SSVC decision (CISA)

Act

Exploitation + impact → act immediately

Exploit maturity

Proof of concept

Popular PoC on GitHub (14 stars) — exploitation code widely available.

CVSS 7.8EPSS 3.1%KEV simPoC públicaNuclei —Metasploit —Patch —

Lifecycle

15 Sep 2021Published on NVD

03 Nov 2021Active exploitation (CISA KEV)

18 Jul 2022Public PoC

Weaponization speed

306 daysto first PoC

49 daysto active exploitation (KEV)

Recommendation: Patch as soon as possible — active exploitation confirmed.

In short

A flaw in Windows' Common Log File System driver allows an attacker with local access to bypass security restrictions and gain higher privileges on the system. This could let them take full control of the computer.

Technical detail

An elevation of privilege vulnerability in the Windows CLFS driver (Kernel component) that can be exploited via local access to escalate from a lower-privileged user context to system-level privileges. Requires prior local code execution; successful exploitation results in SYSTEM-level access.

Summary generated and translated by AI from the official description.

Windows Common Log File System Driver Elevation of Privilege Vulnerability

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C

Affected products

public PoCs found — 2

githubgithub.com/JiaJinRong12138/CVE-2021-36955-EXP★ 14 vulncheckvulncheck.com/xdb/64cb88a140f3unverified

⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.

References

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-36955 https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-36955