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runc AppArmor bypass with symlinked /proc

Moderate severity GitHub Reviewed Published Mar 29, 2023 in opencontainers/runc • Updated Dec 6, 2024

Package

gomod github.com/opencontainers/runc (Go)

Affected versions

< 1.1.5

Patched versions

1.1.5

Description

Impact

It was found that AppArmor, and potentially SELinux, can be bypassed when /proc inside the container is symlinked with a specific mount configuration.

Patches

Fixed in runc v1.1.5, by prohibiting symlinked /proc: opencontainers/runc#3785

This PR fixes CVE-2023-27561 as well.

Workarounds

Avoid using an untrusted container image.

References

@cyphar cyphar published to opencontainers/runc Mar 29, 2023
Published by the National Vulnerability Database Mar 29, 2023
Published to the GitHub Advisory Database Mar 30, 2023
Reviewed Mar 30, 2023
Last updated Dec 6, 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
Local
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Changed
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:L/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(1st percentile)

Weaknesses

Improper Link Resolution Before File Access ('Link Following')

The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource. Learn more on MITRE.

Improper Preservation of Permissions

The product does not preserve permissions or incorrectly preserves permissions when copying, restoring, or sharing objects, which can cause them to have less restrictive permissions than intended. Learn more on MITRE.

CVE ID

CVE-2023-28642

GHSA ID

GHSA-g2j6-57v7-gm8c

Source code

Credits

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