ImageMagick before 6.9.13-58 and 7.x before 7.1.2-33 does not properly account for symbolic links in the IsRightsAuthorizedByName security policy check, allowing configured policy restrictions to be bypassed. Local attackers who can create a symlink can point it at a policy-restricted path to evade the configured policy.
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.
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