CVE-2021-3493

CISA description

The overlayfs stacking file system in Linux kernel does not properly validate the application of file capabilities against user namespaces, which could lead to privilege escalation.

Required action

Apply updates per vendor instructions.

Notes & references

• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7c03e2cda4a584cadc398e8f6641ca9988a39d52
• https://nvd.nist.gov/vuln/detail/CVE-2021-3493

Where this lands in 800-53

Vulnerability data triggers these controls during assessment and continuous monitoring.

• RA-5 · Vulnerability Monitoring and Scanning
• SI-2 · Flaw Remediation
• CM-6 · Configuration Settings
• SI-7 · Software, Firmware, and Information Integrity
• CM-8 · System Component Inventory

External lookups

• NVD · CVE-2021-3493
• CVE.org · CVE-2021-3493
• CISA KEV catalog (canonical)