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Actively exploited · Published Jan 26, 2022 · Assigned by Google

CVE-2021-22600Double Free in net/packet/af_packet.c leading to priviledge escalation

Medium 6.6 Exploited

In plain English

A medium-severity double free in Kernel from Linux Kernel. Attackers are actively exploiting it in the wild (listed by CISA on April 11, 2022). The chance it is exploited in the next 30 days is estimated at 6.6% (higher than 94% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.6Medium
Exploit odds (30 days)6.6%top 6.1% of all CVEs
Exploited in the wildYesCISA KEV since Apr 11, 2022
Attack tooling1Public PoC

CISA guidance

Apply updates per vendor instructions.

Federal agencies must remediate by May 2, 2022.

Official description

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

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux5.15.15-1DEBIAN-CVE-2021-22600
Debian:13linux5.15.15-1DEBIAN-CVE-2021-22600
Debian:14linux5.15.15-1DEBIAN-CVE-2021-22600
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2021-22600
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2021-22600
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2021-22600

Affected products (as reported)

VendorProductVersions
Linux Kernel Kernel unspecified – before 5.4.168unspecified – before 5.10.88unspecified – before 5.15.11unspecified – before 5.16-rc6

Weakness: CWE-415 · Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:H

References