Hermes WebUI prior to v0.51.221 contains a path traversal vulnerability that allows attackers to escape the workspace boundary by supplying symlinks that resolve to files or directories outside the designated workspace root. Attackers can exploit the workspace file and listing APIs, which resolve symlink targets without enforcing that the final path remains within the workspace, to read external host files accessible to the server process and disclose sensitive data such as SSH keys, cloud credentials, or application tokens.
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