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.
Vulnerability Details
The vulnerability is classified as a medium severity issue, with a CVSS score of 5.3. The attack vector is classified as network-based, allowing potential attackers to exploit the flaw remotely. The vulnerability is categorized under CWE-208 (Improper Error Handling) and CWE-203 (Information Exposure Through Discrepancy).
Technical Analysis
The root cause of the vulnerability is a flaw in the authentication logic of the JSONAuth. Auth function. Attackers may leverage this flaw to gain information about existing usernames based on the response time of the /api/login endpoint. The attack complexity is low, and no privileges or user interaction are required to exploit this vulnerability. The confidentiality impact is low, with no integrity or availability impact identified.
Risk & Impact Analysis
Risk to organizations includes unauthorized enumeration of usernames, potentially leading to further attacks such as credential stuffing or phishing. The vulnerability’s exploitation may lead to increased attack surface and compromised user accounts, particularly if users reuse credentials across multiple platforms. Organizations should address this vulnerability in their priority patch cycle to mitigate potential risks.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
All versions prior to vendor patch (version 2.55.0) are affected. This includes all instances of the File Browser application.
Mitigation & Remediation
Organizations should prioritize upgrading to version 2.55.0 or later to mitigate this vulnerability. If an immediate upgrade is not feasible, consider implementing additional network controls such as rate limiting on the /api/login endpoint and monitoring response times for anomalous patterns. For further information on remediation, organizations may refer to penetration testing services to identify the presence of similar vulnerabilities.
Detection Guidance
Monitor logs for repeated failed login attempts and unusual response times from the /api/login endpoint. Behavioral anomalies may indicate an attempt to exploit this vulnerability.
AppSecure Threat Intelligence Insight
This vulnerability highlights the importance of robust authentication mechanisms. Organizations should ensure that error handling does not leak information about valid usernames or other sensitive data. For further insights on best practices, organizations can refer to penetration testing methodology and consider engaging in vulnerability management programs to strengthen their security posture.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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