CVE-2021-32760: Archive package allows chmod of file outside of unpack target directory

Severity: medium (CVSS 6.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-07-19 · updated 2026-06-17
Weakness: CWE-668

Description

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.

Affected products

Fedoraproject Fedora: 34
containerd: before 1.4.8; from 1.5.0 before 1.5.4 — fixed in 1.4.8, 1.5.4

How to fix

Upgrade to a fixed version: containerd 1.4.8, 1.5.4. Check the vendor advisory for mitigations.

References

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