Vulnerability · Published Mar 23, 2022 · Assigned by redhat
CVE-2021-4197
High 7.8
In plain English
A high-severity improper authentication in kernel. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 45% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
An unprivileged write to the file handler flaw in the Linux kernel's control groups and namespaces subsystem was found in the way users have access to some less privileged process that are controlled by cgroups and have higher privileged parent process. It is actually both for cgroup2 and cgroup1 versions of control groups. A local user could use this flaw to crash the system or escalate their privileges on the system.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:8 | bpftool | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-abi-stablelists | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-core | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-cross-headers | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-debug | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-debug-core | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-debug-devel | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-debug-modules | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-debug-modules-extra | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-devel | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-doc | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-headers | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-modules | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-modules-extra | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-tools | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-tools-libs | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-tools-libs-devel | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | perf | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | python3-perf | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| Debian:12 | linux | 5.15.15-1 | DEBIAN-CVE-2021-4197 |
| Debian:13 | linux | 5.15.15-1 | DEBIAN-CVE-2021-4197 |
| Debian:14 | linux | 5.15.15-1 | DEBIAN-CVE-2021-4197 |
| Rocky Linux:8 | kernel | 0:4.18.0-372.9.1.el8 | RLSA-2022:1988 |
| Rocky Linux:8 | kernel-rt | 0:4.18.0-372.9.1.rt7.166.el8 | RLSA-2022:1975 |
| Ubuntu:22.04:LTS | linux-intel-iot-realtime | no fix listed | UBUNTU-CVE-2021-4197 |
| Ubuntu:24.04:LTS | linux-raspi-realtime | no fix listed | UBUNTU-CVE-2021-4197 |
| Ubuntu:22.04:LTS | linux-realtime | no fix listed | UBUNTU-CVE-2021-4197 |
Affected products (as reported)
Weakness: CWE-287
References
- https://bugzilla.redhat.com/show_bug.cgi?id=2035652 x_refsource_MISC
- https://lore.kernel.org/lkml/20211209214707.805617-1-tj%40kernel.org/T/ x_refsource_MISC
- DSA-5127 vendor-advisory, x_refsource_DEBIAN
- DSA-5173 vendor-advisory, x_refsource_DEBIAN
- https://www.oracle.com/security-alerts/cpujul2022.html x_refsource_MISC
- https://security.netapp.com/advisory/ntap-20220602-0006/ x_refsource_CONFIRM