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Archive package allows chmod of file outside of unpack target directory

Moderate severity GitHub Reviewed Published Jul 19, 2021 in containerd/containerd • Updated Jan 31, 2024

Package

gomod github.com/containerd/containerd (Go)

Affected versions

< 1.4.8
>= 1.5.0, < 1.5.4

Patched versions

1.4.8
1.5.4

Description

Impact

A bug was found in containerd 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.

Patches

This bug has been fixed in containerd 1.5.4 and 1.4.8. Users should update to these versions as soon as they are released. Running containers do not need to be restarted.

Workarounds

Ensure you 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 unexpected files.

For more information

If you have any questions or comments about this advisory:

References

@dmcgowan dmcgowan published to containerd/containerd Jul 19, 2021
Published by the National Vulnerability Database Jul 19, 2021
Reviewed Jul 22, 2021
Published to the GitHub Advisory Database Jul 26, 2021
Last updated Jan 31, 2024

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
Low

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:L

EPSS score

0.202%
(58th percentile)

Weaknesses

CVE ID

CVE-2021-32760

GHSA ID

GHSA-c72p-9xmj-rx3w

Source code

Credits

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