CVE-2020-11050
📋 TL;DR
This vulnerability allows man-in-the-middle attacks against Java-WebSocket clients by exploiting improper SSL certificate hostname validation. Attackers can intercept and manipulate WebSocket communications when clients connect to malicious servers. Any application using Java-WebSocket library version 1.4.1 or earlier is affected.
💻 Affected Systems
- Java-WebSocket library
📦 What is this software?
Java Websocket by Java Websocket Project
⚠️ Risk & Real-World Impact
Worst Case
Complete interception and manipulation of all WebSocket communications, potentially leading to data theft, session hijacking, or injection of malicious content.
Likely Case
Man-in-the-middle attacks in compromised network environments allowing eavesdropping on WebSocket traffic and potential credential theft.
If Mitigated
Limited impact if proper network segmentation and certificate validation are enforced elsewhere in the application stack.
🎯 Exploit Status
Exploitation requires man-in-the-middle position but is straightforward once network access is obtained.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.5.0
Vendor Advisory: https://github.com/TooTallNate/Java-WebSocket/security/advisories/GHSA-gw55-jm4h-x339
Restart Required: Yes
Instructions:
1. Update Java-WebSocket dependency to version 1.5.0 or later
2. Update pom.xml or build.gradle to specify new version
3. Rebuild and redeploy application
4. Restart affected services
🔧 Temporary Workarounds
Implement custom SSL hostname validation
allOverride WebSocketClient to add proper hostname validation before establishing connections
Use certificate pinning
allImplement certificate pinning to validate server certificates against known good certificates
🧯 If You Can't Patch
- Isolate vulnerable applications in segmented network zones with strict egress controls
- Monitor network traffic for unexpected WebSocket connections and certificate validation failures
🔍 How to Verify
Check if Vulnerable:
Check Java-WebSocket library version in application dependencies; if version <= 1.4.1, it's vulnerableCheck Version:
Check build configuration files (pom.xml, build.gradle) or run: java -cp "your-app.jar" -Djava.security.debug=certpathVerify Fix Applied:
Verify Java-WebSocket version is 1.5.0 or later and test SSL/TLS connections with invalid hostname certificates📡 Detection & Monitoring
Log Indicators:
- SSL/TLS handshake failures
- Certificate validation errors
- Unexpected WebSocket connection attempts
Network Indicators:
- WebSocket traffic to unexpected destinations
- SSL/TLS connections with certificate hostname mismatches
SIEM Query:
source="*ssl*" AND ("certificate" AND "hostname" AND "mismatch") OR source="*websocket*" AND event="connection_failure"