CVE-2025-21622
📋 TL;DR
This CVE describes a path traversal vulnerability in ClipBucket V5's avatar upload feature. Attackers can delete arbitrary files on the server by manipulating avatar URLs with directory traversal sequences. All ClipBucket V5 installations below version 5.5.1-237 are affected.
💻 Affected Systems
- ClipBucket V5
📦 What is this software?
Clipbucket by Oxygenz
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise through deletion of critical system files, configuration files, or web application files leading to denial of service or privilege escalation.
Likely Case
Selective file deletion causing application malfunction, data loss, or partial system disruption.
If Mitigated
Limited to avatar directory operations with proper input validation and path sanitization.
🎯 Exploit Status
Requires authenticated user access and knowledge of target file paths. No public exploit code available as of analysis.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 5.5.1-237
Vendor Advisory: https://github.com/MacWarrior/clipbucket-v5/security/advisories/GHSA-5qpx-23rw-36gg
Restart Required: No
Instructions:
1. Backup your ClipBucket installation and database. 2. Download version 5.5.1-237 or later from the official repository. 3. Replace affected files with patched versions. 4. Verify the fix by checking the avatar upload functionality.
🔧 Temporary Workarounds
Input Validation Filter
allAdd server-side validation to reject avatar URLs containing path traversal sequences like '../' or absolute paths.
Modify avatar handling code to sanitize input using realpath() and basename() functions
File Deletion Restriction
allRestrict file deletion operations to only files within the avatars directory using directory whitelisting.
Implement checks to ensure $file variable starts with avatars/ directory path before deletion
🧯 If You Can't Patch
- Disable avatar upload functionality completely in user settings or configuration
- Implement web application firewall (WAF) rules to block requests containing path traversal sequences in avatar URLs
🔍 How to Verify
Check if Vulnerable:
Check if your ClipBucket version is below 5.5.1-237 by examining version files or admin panel.Check Version:
Check includes/version.php or admin panel for version numberVerify Fix Applied:
Test avatar upload with malicious path traversal sequences; system should reject or sanitize the input instead of deleting files.📡 Detection & Monitoring
Log Indicators:
- Unusual file deletion events outside avatars directory
- HTTP requests with '../' sequences in avatar parameters
- Error logs showing failed file operations with traversal paths
Network Indicators:
- HTTP POST requests to avatar update endpoints with suspicious path parameters
SIEM Query:
web_access_logs WHERE url_parameters CONTAINS '../' AND endpoint LIKE '%avatar%'