File Browser provides a file managing interface within a specified directory and can be used to upload, delete, preview, rename, and edit files. Prior to version 2.55.0, the JSONAuth. Auth function contains a logic flaw that allows unauthenticated attackers to enumerate valid usernames by measuring the response time of the /api/login endpoint. The vulnerability exists due to a short-circuit evaluation in the authentication logic. When a username is not found in the database, the function returns immediately. However, if the username does exist, the code proceeds to verify the password using bcrypt (users.CheckPwd), which is a computationally expensive operation designed to be slow. This difference in execution path creates a measurable timing discrepancy. Version 2.55.0 contains a patch for the issue.
Weakness
Two separate operations in a product require different amounts of time to complete, in a way that is observable to an actor and reveals security-relevant information about the state of the product, such as whether a particular operation was successful or not.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Filebrowser | Filebrowser | * | 2.55.0 (excluding) |
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/462.html
- https://cwe.mitre.org/data/definitions/541.html
- https://cwe.mitre.org/data/definitions/580.html