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Vulnerability · Published Feb 4, 2022 · Assigned by redhat

CVE-2021-4154

High 8.8

In plain English

A high-severity use-after-free in kernel. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.2% (higher than 69% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)8.8High
Exploit odds (30 days)1.2%top 31.3% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack tooling1Public PoC

Official description

A use-after-free flaw was found in cgroup1_parse_param in kernel/cgroup/cgroup-v1.c in the Linux kernel's cgroup v1 parser. A local attacker with a user privilege could cause a privilege escalation by exploiting the fsconfig syscall parameter leading to a container breakout and a denial of service on the system.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
AlmaLinux:8kernel-tools-libs-devel4.18.0-348.20.1.el8_5ALSA-2022:0825
Debian:12linux5.14.6-1DEBIAN-CVE-2021-4154
Debian:13linux5.14.6-1DEBIAN-CVE-2021-4154
Debian:14linux5.14.6-1DEBIAN-CVE-2021-4154
Rocky Linux:8kernel0:4.18.0-348.20.1.el8_5RLSA-2022:0825
Rocky Linux:8kernel-rt0:4.18.0-348.20.1.rt7.150.el8_5RLSA-2022:0819
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2021-4154
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2021-4154
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2021-4154

Affected products (as reported)

VendorProductVersions
n/a kernel Fixed in kernel 5.14 rc2

Weakness: CWE-416

References