CVE-2021-22600: Linux Kernel Privilege Escalation via AF_PACKET Memory Free Bug
What It Is — The Linux kernel’s packet‑socket (AF_PACKET) implementation contains a memory‑free error that can be triggered by a local user.
Exploitability — No public exploit is known, but proof‑of‑concept code exists; the flaw can cause denial‑of‑service or potentially allow privilege escalation. CVSS v3.1 base score 7.8 (High).
Affected Products — All Linux distributions shipping kernel versions prior to the patch released in March 2022 (e.g., Ubuntu 20.04, RHEL 8, Debian 10, etc.).
Why It Matters for Trust & Control Assurance
- Continuous patch‑management evidence demonstrates due‑diligence and satisfies audit requirements across frameworks.
- Verifiable remediation provides a defensible audit trail for privileged‑access controls.
- Demonstrating timely remediation signals a mature control environment to enterprise buyers.
Recommended Actions
- Deploy the kernel update that resolves CVE‑2021‑22600 on all Linux assets.
- Update your asset inventory and patch‑status dashboards to capture remediation evidence.
- Enable continuous monitoring to alert on any unpatched hosts and retain logs for audit purposes.
Source: CISA KEV – CVE‑2021‑22600