Vulnerability · Published Feb 18, 2022 · Assigned by redhat
CVE-2021-20321
Medium 4.7
In plain English
A medium-severity race condition in kernel. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 12% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS NVD)4.7Medium
Exploit odds (30 days)0.2%top 87.9% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known
Official description
A race condition accessing file object in the Linux kernel OverlayFS subsystem was found in the way users do rename in specific way with OverlayFS. A local user could use this flaw to crash the system.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:8 | kernel-tools-libs-devel | 4.18.0-348.7.1.el8_5 | ALSA-2021:5227 |
| Debian:12 | linux | 5.14.12-1 | DEBIAN-CVE-2021-20321 |
| Debian:13 | linux | 5.14.12-1 | DEBIAN-CVE-2021-20321 |
| Debian:14 | linux | 5.14.12-1 | DEBIAN-CVE-2021-20321 |
| Rocky Linux:8 | kernel | 0:4.18.0-348.7.1.el8_5 | RLSA-2021:5227 |
| Rocky Linux:8 | kernel-rt | 0:4.18.0-348.7.1.rt7.137.el8_5 | RLSA-2021:5241 |
| Ubuntu:22.04:LTS | linux-intel-iot-realtime | no fix listed | UBUNTU-CVE-2021-20321 |
| Ubuntu:24.04:LTS | linux-raspi-realtime | no fix listed | UBUNTU-CVE-2021-20321 |
| Ubuntu:22.04:LTS | linux-realtime | no fix listed | UBUNTU-CVE-2021-20321 |
Affected products (as reported)
Weakness: CWE-362
References
- https://bugzilla.redhat.com/show_bug.cgi?id=2013242 x_refsource_MISC
- https://lore.kernel.org/all/20211011134508.748956131%40linuxfoundation.org/ x_refsource_MISC
- [debian-lts-announce] 20220309 [SECURITY] [DLA 2941-1] linux-4.19 security update mailing-list, x_refsource_MLIST
- DSA-5096 vendor-advisory, x_refsource_DEBIAN