CVE-2025-68148
📋 TL;DR
This vulnerability in FreshRSS allows attackers to globally deny access to RSS feeds by manipulating proxy responses to return HTTP 429 Retry-After headers for multiple feeds. This makes the instance unusable for most users through a denial-of-service attack. Only self-hosted FreshRSS instances running versions 1.27.0 through 1.27.x are affected.
💻 Affected Systems
- FreshRSS
📦 What is this software?
Freshrss by Freshrss
⚠️ Risk & Real-World Impact
Worst Case
Complete denial of service where all users lose access to RSS feeds, rendering the FreshRSS instance unusable until manually restored or patched.
Likely Case
Partial or intermittent feed access issues affecting multiple users, requiring administrator intervention to restore normal functionality.
If Mitigated
Minimal impact with proper proxy filtering and rate limiting in place, potentially causing temporary feed access issues for some users.
🎯 Exploit Status
Attack requires ability to manipulate proxy responses returning 429 Retry-After headers for multiple feeds.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.28.0
Vendor Advisory: https://github.com/FreshRSS/FreshRSS/security/advisories/GHSA-qw34-frg7-gf78
Restart Required: No
Instructions:
1. Backup your FreshRSS installation and database. 2. Download FreshRSS version 1.28.0 or later from the official repository. 3. Replace the existing installation files with the new version. 4. Verify the update completed successfully.
🔧 Temporary Workarounds
Disable proxy functionality
allTemporarily disable proxy usage for feed fetching if not required
Edit FreshRSS configuration to remove or comment out proxy settings
Implement proxy filtering
allConfigure network proxy to filter or block 429 Retry-After responses
Configure proxy server to intercept and modify 429 responses
🧯 If You Can't Patch
- Implement network-level rate limiting and filtering for 429 responses
- Monitor proxy logs for unusual 429 Retry-After patterns and block offending IPs
🔍 How to Verify
Check if Vulnerable:
Check FreshRSS version in admin interface or by examining version files in installation directoryCheck Version:
Check FreshRSS admin panel or grep for version in installation filesVerify Fix Applied:
Confirm version is 1.28.0 or later and test feed fetching through proxy📡 Detection & Monitoring
Log Indicators:
- Multiple 429 Retry-After responses from proxy for different feeds
- Unusual increase in feed fetch failures
Network Indicators:
- Suspicious proxy traffic patterns
- Multiple HTTP 429 responses from single source
SIEM Query:
proxy_response_code=429 AND destination_port=80 OR destination_port=443 AND count>threshold