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CVE-2021-22600

Medium CVSS 6.6 Known exploited

Published 2022-01-26 · last changed 2026-06-17 · added to CISA KEV 2022-04-11

This one is being exploited in the wild.

CISA added CVE-2021-22600 to the Known Exploited Vulnerabilities catalog on 2022-04-11. Federal agencies are required to remediate it on a deadline. If you have affected machines, this is the class of finding that moves ahead of the rest of the queue.

The fix

We hold no Microsoft remediation data for CVE-2021-22600, which normally means it is not a Windows CVE. For non-Microsoft software the fix is the vendor's own updated release, and the affected versions are listed below.

What it is

A double free bug in packet_set_ring() in net/packet/af_packet.c can be exploited by a local user through crafted syscalls to escalate privileges or deny service. We recommend upgrading kernel past the effected versions or rebuilding past ec6af094ea28f0f2dda1a6a33b14cd57e36a9755

Sources

CVSS vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:H