CVE-2026-21875
📋 TL;DR
ClipBucket v5 versions 5.5.2-#187 and below contain a blind SQL injection vulnerability in the comment functionality. Attackers can exploit this by injecting malicious SQL payloads through the obj_id parameter when adding comments to channels, potentially allowing unauthorized database access. All users running vulnerable versions are affected.
💻 Affected Systems
- ClipBucket v5
📦 What is this software?
Clipbucket by Oxygenz
⚠️ Risk & Real-World Impact
Worst Case
Complete database compromise including exfiltration of sensitive user data, authentication bypass, privilege escalation, and potential remote code execution through database functions.
Likely Case
Data exfiltration of user information, comments, and potentially hashed passwords, leading to credential theft and account takeover.
If Mitigated
Limited impact with proper input validation and WAF rules blocking SQL injection patterns.
🎯 Exploit Status
Exploitation requires user authentication to access the comment functionality, but the SQL injection technique is straightforward once authenticated.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: None available
Vendor Advisory: https://github.com/MacWarrior/clipbucket-v5/security/advisories/GHSA-crpv-fmc4-j392
Restart Required: No
Instructions:
No official patch exists. Consider workarounds or migrating to alternative software.
🔧 Temporary Workarounds
Input Validation and Sanitization
allImplement server-side validation and parameterized queries for the obj_id parameter in the user_exists function.
Modify upload/includes/classes/user.class.php to validate obj_id as integer
Modify upload/includes/classes/db.class.php to use prepared statements
WAF Rule Implementation
allDeploy web application firewall rules to block SQL injection patterns targeting the /actions/ajax.php endpoint.
Add WAF rule: Detect SQL injection patterns in POST parameters to /actions/ajax.php
🧯 If You Can't Patch
- Disable comment functionality in channels completely
- Implement network segmentation to restrict database access from application servers
🔍 How to Verify
Check if Vulnerable:
Check if your ClipBucket version is 5.5.2-#187 or earlier by examining the version file or admin panel.Check Version:
Check upload/version.txt or admin panel version informationVerify Fix Applied:
Test the comment functionality with SQL injection payloads to ensure they are properly rejected.📡 Detection & Monitoring
Log Indicators:
- Unusual SQL error messages in application logs
- Multiple failed comment attempts with special characters
- Unusually long obj_id parameter values
Network Indicators:
- POST requests to /actions/ajax.php containing SQL keywords in parameters
- Unusual database query patterns from application server
SIEM Query:
source="web_logs" AND uri="/actions/ajax.php" AND (param="obj_id" AND value MATCHES "[';]|OR|UNION|SELECT")