CVE-2023-43116

A symbolic link following vulnerability in Buildkite Elastic CI for AWS versions prior to 6.7.1 and 5.22.5 allows the buildkite-agent user to change ownership of arbitrary directories via the PIPELINE_PATH variable in the fix-buildkite-agent-builds-permissions script.

Weakness

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.

Affected Software

Potential Mitigations

• Follow the principle of least privilege when assigning access rights to entities in a software system.
• Denying access to a file can prevent an attacker from replacing that file with a link to a sensitive file. Ensure good compartmentalization in the system to provide protected areas that can be trusted.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/132.html
• https://cwe.mitre.org/data/definitions/17.html
• https://cwe.mitre.org/data/definitions/35.html
• https://cwe.mitre.org/data/definitions/76.html

References

• https://github.com/atredispartners/advisories/blob/master/ATREDIS-2023-0003.md