Windows Common Log File System Driver Elevation of Privilege Vulnerability

Successful exploitation allows a local attacker to elevate privileges on the affected Windows host. Based on the provided content, the vulnerability is a high-severity local privilege escalation issue and has been reported as actively exploited in the wild, including later inclusion in CISA's Known Exploited Vulnerabilities catalog. This can enable an attacker who already has code execution in a low-privilege context to obtain higher privileges and potentially full system compromise.

Because this is a local privilege escalation vulnerability, mitigations are limited compared with patching. Until patches can be applied, reduce opportunities for local code execution by restricting user access, minimizing interactive logon rights, enforcing least privilege, monitoring for suspicious post-exploitation behavior, and isolating or hardening high-risk or legacy systems. Prioritize systems exposed to untrusted users or already suspected of compromise.

Apply the relevant Microsoft security update for CVE-2021-43226 to affected Windows systems. The content also indicates CISA KEV inclusion, so remediation should be prioritized in accordance with organizational vulnerability management and any applicable compliance deadlines. Where possible, verify patch deployment across all affected endpoints and servers.