CVE-2020-26304
📋 TL;DR
Foundation front-end framework versions 6.3.3 and earlier contain vulnerable regular expressions that can be exploited for Regular Expression Denial of Service (ReDoS). Attackers can cause excessive CPU consumption by crafting malicious input, potentially making web applications unresponsive. This affects any website or application using vulnerable Foundation framework versions.
💻 Affected Systems
- Foundation Sites
📦 What is this software?
Foundation by Foundation
⚠️ Risk & Real-World Impact
Worst Case
Complete denial of service causing application unavailability, potentially affecting all users of the vulnerable application.
Likely Case
Degraded performance and intermittent service disruptions when attackers target vulnerable endpoints.
If Mitigated
Minimal impact with proper input validation, rate limiting, and monitoring in place.
🎯 Exploit Status
Exploitation requires sending specially crafted input to endpoints using vulnerable regex patterns.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: https://github.com/foundation/foundation-sites/issues/12180
Restart Required: No
Instructions:
1. Monitor Foundation GitHub repository for updates. 2. Check if newer versions beyond 6.3.3 are available. 3. Update Foundation framework if patched version is released.
🔧 Temporary Workarounds
Input Validation and Sanitization
allImplement strict input validation and sanitization for all user inputs before processing with Foundation functions.
Rate Limiting
allImplement rate limiting on endpoints that process user input to prevent DoS attacks.
🧯 If You Can't Patch
- Implement Web Application Firewall (WAF) rules to detect and block malicious regex patterns
- Monitor CPU usage and implement alerting for abnormal regex processing times
🔍 How to Verify
Check if Vulnerable:
Check package.json or framework version in your application for Foundation version 6.3.3 or earlier.Check Version:
Check package.json for "foundation-sites" version or inspect framework files for version information.Verify Fix Applied:
Verify Foundation version is updated beyond 6.3.3 and test input validation on affected endpoints.📡 Detection & Monitoring
Log Indicators:
- Unusually long processing times for input validation
- High CPU usage spikes
- Multiple failed requests with similar patterns
Network Indicators:
- Repeated requests with specially crafted strings
- Abnormal request patterns targeting input endpoints
SIEM Query:
source="web_server" AND (message="*long processing time*" OR message="*CPU spike*" OR status=500) AND uri="*input*"