Use-after-free in Linux kernel - CVE-2021-4154
Published: January 19, 2022 / Updated: August 11, 2022
Vulnerability identifier: #VU59840
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Clear
CVE-ID: CVE-2021-4154
CWE-ID: CWE-416
Exploitation vector: Local access
Exploit availability:
Public exploit is available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a use-after-free error within the cgroup1_parse_param() function in kernel/cgroup/cgroup-v1.c in Linux kernel's cgroup v1 parser. A local user can execute arbitrary code via the fsconfig syscall parameter leading to a container breakout.
How to mitigate CVE-2021-4154
Install updates from vendor's website.