SmarterTools SmarterMail versions prior to build 9518 contain an unauthenticated path coercion vulnerability in the background-of-the-day preview endpoint. The application base64-decodes attacker-supplied input and uses it as a filesystem path without validation. On Windows systems, this allows UNC paths to be resolved, causing the SmarterMail service to initiate outbound SMB authentication attempts to attacker-controlled hosts. This can be abused for credential coercion, NTLM relay attacks, and unauthorized network authentication.
Weakness
The product uses a name or reference to access a resource, but the name/reference resolves to a resource that is outside of the intended control sphere.
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/159.html
- https://cwe.mitre.org/data/definitions/177.html
- https://cwe.mitre.org/data/definitions/48.html
- https://cwe.mitre.org/data/definitions/641.html