VideoLAN VLC for Android prior to version 3.7.0 contains an authentication bypass in the Remote Access Server feature due to missing or insufficient rate limiting on one-time password (OTP) verification. The Remote Access Server uses a 4-digit OTP and does not enforce effective throttling or lockout within the OTP validity window, allowing an attacker with network reachability to the server to repeatedly attempt OTP verification until a valid user_session cookie is issued. Successful exploitation results in unauthorized access to the Remote Access interface, limited to media files explicitly shared by the VLC for Android user.
Weakness
The product does not implement sufficient measures to prevent multiple failed authentication attempts within a short time frame.
Potential Mitigations
Common protection mechanisms include:
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid [REF-1482].
Consider using libraries with authentication capabilities such as OpenSSL or the ESAPI Authenticator. [REF-45]
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/16.html
- https://cwe.mitre.org/data/definitions/49.html
- https://cwe.mitre.org/data/definitions/560.html
- https://cwe.mitre.org/data/definitions/565.html
- https://cwe.mitre.org/data/definitions/600.html
- https://cwe.mitre.org/data/definitions/652.html
- https://cwe.mitre.org/data/definitions/653.html
References
- https://https://github.com/videolan/vlc-android/releases/tag/3.7.0
- https://www.videolan.org/vlc/download-android.html
- https://www.vulncheck.com/advisories/vlc-for-android-remote-access-otp-authentication-bypass