Executive Summary

This vulnerability is a Time-of-Check to Time-of-Use (TOCTOU) flaw in the chcon utility of uutils coreutils during recursive operations. It occurs because the utility resolves recursive targets using a fresh path lookup instead of binding the traversal and label application to the specific directory state encountered during traversal. This means that a local attacker with write access to a directory tree can exploit timing-sensitive rename or symbolic link races to redirect a privileged recursive relabeling operation to unintended files or directories.

As a result, the vulnerability breaks the hardening expectations for SELinux administration workflows and can lead to unauthorized modification of security labels on sensitive system objects.

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Impact Analysis

This vulnerability can allow a local attacker with write access to a directory tree to manipulate privileged recursive relabeling operations. By exploiting timing-sensitive rename or symbolic link races, the attacker can redirect these operations to unintended files or directories.

The impact includes unauthorized modification of security labels on sensitive system objects, potentially weakening the security posture of the system and allowing further unauthorized actions.

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Compliance Impact

This vulnerability allows unauthorized modification of security labels on sensitive system objects by exploiting a race condition in recursive SELinux relabel operations. Such unauthorized modifications can undermine the integrity and security of system controls that protect sensitive data.

Because standards like GDPR and HIPAA require strict controls over access and protection of sensitive data, this vulnerability could potentially lead to non-compliance by enabling attackers to bypass security mechanisms and alter security labels, thereby compromising data protection measures.

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Detection Guidance

This vulnerability is a timing-sensitive race condition in the chcon utility during recursive SELinux relabel operations. Because it involves local file system races with rename or symbolic link operations, detection requires monitoring for unexpected or unauthorized changes to SELinux security labels on files or directories.

There are no specific commands provided in the available information to directly detect this vulnerability on your system or network.

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Mitigation Strategies

To mitigate this vulnerability, ensure that you update the uutils coreutils package to a version that includes the fix described in the referenced pull request (#11402). This fix anchors recursive relabel operations to the traversal directory file descriptor, preventing the race condition.

Additionally, restrict write access to directory trees where SELinux relabeling operations are performed to trusted users only, minimizing the risk of local attackers exploiting rename or symbolic link races.

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