Vulnerability in Containerd
CVE-2021-32760
containerd is a container runtime. A bug was found in containerd versions prior to 1.4.8 and 1.5.4 where pulling and extracting a specially-crafted container image can result in Unix file permission changes for existing files in the host’s filesystem. Changes to file permissions can deny access to the expected owner of the file, widen access to others, or set extended bits like setuid, setgid, and sticky. This bug does not directly allow files to be read, modified, or executed without an additional cooperating process. This bug has been fixed in containerd 1.5.4 and 1.4.8. As a workaround, ensure that users only pull images from trusted sources. Linux security modules (LSMs) like SELinux and AppArmor can limit the files potentially affected by this bug through policies and profiles that prevent containerd from interacting with specific files.
EPSS: 0.016 (73.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.0 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:L.
Affected products
- Containerd — versions <= 1.4.7, >= 1.5.0, <= 1.5.3
- Linuxfoundation Containerd
- Fedoraproject Fedora — versions 34
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security-advisories@github.com (Third Party Advisory)
- security-advisories@github.com (Third Party Advisory, Release Notes)
- security-advisories@github.com (Third Party Advisory, Release Notes)
- security-advisories@github.com (vendor-advisory)
- security-advisories@github.com (vendor-advisory)
Frequently asked questions
- What is CVE-2021-32760?
- CVE-2021-32760 is a medium-severity vulnerability in Containerd, classified under Exposure of Resource to Wrong Sphere. CVSS score: 5.0/10. Published 2021-07-19.
- How severe is CVE-2021-32760?
- Medium severity. CVSS v3 base score is 5.0 out of 10.
- Is CVE-2021-32760 known to be exploited?
- 5 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.