cbcvebase.
CVE-2022-0492
published 2022-03-03

CVE-2022-0492: A vulnerability was found in the Linux kernel’s cgroup_release_agent_write in the kernel/cgroup/cgroup-v1.c function. This flaw, under certain circumstances…

PriorityP183high7.8CVSS 3.1
AVLACLPRLUINSUCHIHAH
KEVITWEXPLOIT
CISA Known Exploited Vulnerabilitydue 2026-06-05
Exploited in the wild
EPSS
5.53%
91.9th percentile
A vulnerability was found in the Linux kernel’s cgroup_release_agent_write in the kernel/cgroup/cgroup-v1.c function. This flaw, under certain circumstances, allows the use of the cgroups v1 release_agent feature to escalate privileges and bypass the namespace isolation unexpectedly.

Affected

56 ranges· showing 25
VendorProductVersion rangeFixed in
canonicalubuntu_linux
canonicalubuntu_linux
canonicalubuntu_linux
canonicalubuntu_linux
canonicalubuntu_linux
debiandebian_linux
debiandebian_linux
debiandebian_linux
debianlinux< linux 5.16.7-1 (bookworm)linux 5.16.7-1 (bookworm)
fedoraprojectfedora
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel>= 0 < 5.10.103-15.10.103-1
linuxlinux_kernel>= 0 < 5.16.7-15.16.7-1
linuxlinux_kernel>= 0 < 5.16.7-15.16.7-1
linuxlinux_kernel>= 0 < 5.16.7-15.16.7-1
linuxlinux_kernel>= 0 < 4.15.0-173.1824.15.0-173.182
linuxlinux_kernel>= 0 < 5.4.0-105.1195.4.0-105.119
linuxlinux_kernel>= 0 < 4.4.0-222.2554.4.0-222.255
linuxlinux_kernel>= 0 < 4.4.0-227.2614.4.0-227.261
linuxlinux_kernel>= 0 < 4.15.0-180.1894.15.0-180.189
linuxlinux_kernel>= 0 < 4.15.0-173.1824.15.0-173.182
linuxlinux_kernel>= 0 < 5.4.0-117.1325.4.0-117.132
linuxlinux_kernel>= 0 < 5.4.0-105.1195.4.0-105.119
linuxlinux_kernel>= 0 < 5.15.0-37.395.15.0-37.39

Detection & IOCsextracted from sources · hover to see the quote

path/sys/fs/cgroup/memory/release_agent
path/sys/fs/cgroup/memory/a_child_cgroup/notify_on_release
  • Monitor for writes to the cgroups v1 release_agent file (e.g. /sys/fs/cgroup/*/release_agent) from within container processes, which is the core exploitation primitive for CVE-2022-0492.
  • Detect use of the unshare() syscall from within containers to create new user and cgroup namespaces, a required step for unprivileged container escape via CVE-2022-0492.
  • Alert on cgroupfs mount operations originating from inside a container, especially mounting the memory or RDMA cgroup subsystem, as this is a prerequisite for exploitation.
  • Flag containers running without AppArmor, SELinux, or Seccomp profiles, as these are the configurations vulnerable to container escape via CVE-2022-0492.
  • Detect containers running in the root cgroup of a subsystem (e.g. root RDMA cgroup), as this is required for the release_agent file to be visible and exploitable.
  • Monitor writes to notify_on_release files within cgroupfs from container processes, as enabling this is a required step in the exploitation chain.
  • ·Exploitation requires the container to run without AppArmor, SELinux, or Seccomp — containers protected by any of these are not vulnerable to escape via this CVE.
  • ·The host must have unprivileged user namespaces enabled (default on recent Ubuntu releases) for the namespace-based exploitation path to work.
  • ·Only cgroups v1 is affected; cgroups v2 environments are not vulnerable.
  • ·Exploitation requires the container process to run as root (or have CAP_DAC_OVERRIDE), since the release_agent file is owned by root.
  • ·The vulnerability is especially dangerous in containerized environments using cgroups v1 when containers are granted elevated capabilities.
  • ·Fixed kernel versions include 4.9.301+, 4.14.266+, 4.19.229+, 5.4.177+, 5.10.97+, 5.15.20+, 5.16.6+, and 5.17-rc3+.

CVSS provenance

nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
nvdv2.06.9MEDIUMAV:L/AC:M/Au:N/C:C/I:C/A:C
osv7.8HIGH
vulncheck7.8HIGH
cisa7.8HIGH
vendor_debian7.8HIGH
vendor_msrc7.8HIGH
vendor_oracle7.8HIGH
vendor_redhat7.8HIGH
vendor_ubuntu7.8HIGH
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