FileRise: Rate Limiting Bypass via Username Rotation Enables Unlimited Password Spraying

FileRise is a self-hosted web-based file manager with multi-file upload, editing, and batch operations. Prior to 3.21.0, FileRise tracks failed logins only by the combination of source IP address and username. A remote unauthenticated attacker can rotate usernames to obtain a fresh per-account attempt budget for each name, enabling password spraying from one source beyond the intended limit. Per-user limits still apply and can also produce distinguishable throttling behavior for targeted accounts. The affected surface is AuthModel::getFailedLoginKey(). This issue is fixed in version 3.21.0.