CVE-2025-55737
📋 TL;DR
This vulnerability in flaskBlog allows any authenticated user to delete arbitrary comments belonging to other users by manipulating the commentID parameter in delete requests. It affects all users of flaskBlog versions 2.8.0 and earlier who have comment functionality enabled. The issue stems from missing authorization checks in the comment deletion endpoint.
💻 Affected Systems
- flaskBlog
📦 What is this software?
Flaskblog by Dogukanurker
⚠️ Risk & Real-World Impact
Worst Case
Malicious users could systematically delete all comments on a blog, causing data loss, disrupting discussions, and potentially enabling harassment campaigns by removing victim responses.
Likely Case
Users deleting comments they shouldn't have access to, leading to data integrity issues, user complaints, and potential moderation bypass.
If Mitigated
With proper authorization checks, only comment owners or administrators can delete comments, maintaining data integrity and user trust.
🎯 Exploit Status
Exploitation requires authenticated access but is trivial via parameter manipulation in HTTP requests.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.8.1 or later
Vendor Advisory: https://github.com/DogukanUrker/FlaskBlog/security/advisories/GHSA-6hp9-jv2f-88wr
Restart Required: No
Instructions:
1. Update flaskBlog to version 2.8.1 or later. 2. Review routes/post.py to ensure authorization checks are implemented. 3. Test comment deletion functionality.
🔧 Temporary Workarounds
Disable comment deletion
allTemporarily disable the comment deletion endpoint until patching is possible
Comment out or remove the comment deletion route in routes/post.py
Add authorization middleware
allImplement authorization checks before processing delete requests
Add ownership verification before comment deletion in routes/post.py
🧯 If You Can't Patch
- Implement web application firewall rules to monitor and block suspicious comment deletion patterns
- Enable detailed logging of all comment deletion attempts and regularly review for unauthorized activity
🔍 How to Verify
Check if Vulnerable:
Test if authenticated user can delete another user's comment by modifying commentID parameter in delete requestCheck Version:
Check flaskBlog version in package metadata or application configurationVerify Fix Applied:
Verify that only comment owners or administrators can delete comments after update📡 Detection & Monitoring
Log Indicators:
- Multiple failed authorization attempts for comment deletion
- User deleting comments with IDs not associated with their account
- Unusual patterns of comment deletion activity
Network Indicators:
- HTTP DELETE requests to comment endpoints with mismatched user-comment relationships
- Parameter tampering in comment deletion requests
SIEM Query:
source="flaskblog" AND (action="delete_comment" AND user_id != comment_owner_id)