CVE Database›Document archive›CVE-2021-4154

CVE-2021-4154

kernel: local privilege escalation by exploiting the fsconfig syscall parameter leads to container breakout

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Severity

Important

Red Hat Product Security

8.8

CVSS 3.1

Review impact separately from score.

Published · December 14, 2021

Updated · June 28, 2026

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.

CVSS score applicability

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.

CVSS / CWE

CVSS 3.1 · 8.8
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

CWE-416 · Use After Free