Sync-in Server is a secure, open-source platform for file storage, sharing, collaboration, and syncing. Prior to version 2.2.0, the /api/auth/login endpoint contains a logic flaw that allows unauthenticated remote attackers to enumerate valid usernames by measuring the application's response time. This issue has been patched in version 2.2.0.

A Stored Cross-Site Scripting (XSS) vulnerability in Sync-in Server before 1.9.3 allows an authenticated attacker to execute arbitrary JavaScript in a victim's browser. By uploading a crafted SVG file containing a malicious payload, an attacker can access and exfiltrate sensitive information, including the user's session cookies.

Directory traversal vulnerability in Sync In server thru 1.1.1 allowing authenticated attackers to gain read and write access to the system via FilesManager.saveMultipart function in backend/src/applications/files/services/files-manager.service.ts, and FilesManager.compress function in backend/src/applications/files/services/files-manager.service.ts.