CVE-2022-36971
📋 TL;DR
This vulnerability in Ivanti Avalanche allows authenticated remote attackers to bypass authentication mechanisms and execute arbitrary code via insecure deserialization in the JwtTokenUtility class. Attackers can gain code execution in the context of the service account. Affected systems are Ivanti Avalanche installations version 6.3.2.3490.
💻 Affected Systems
- Ivanti Avalanche
📦 What is this software?
Avalanche by Ivanti
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with attacker gaining service account privileges, enabling lateral movement, data exfiltration, and persistent backdoor installation.
Likely Case
Remote code execution leading to service disruption, data theft, and potential ransomware deployment.
If Mitigated
Limited impact with proper network segmentation and authentication controls, though still significant due to authentication bypass.
🎯 Exploit Status
Authentication bypass reduces exploitation barrier. ZDI advisory suggests weaponization is likely given the high impact.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 6.3.4
Vendor Advisory: https://download.wavelink.com/Files/avalanche_v6.3.4_release_notes.txt
Restart Required: Yes
Instructions:
1. Download Ivanti Avalanche 6.3.4 from official sources. 2. Backup current configuration and data. 3. Install the update following vendor documentation. 4. Restart the Avalanche service.
🔧 Temporary Workarounds
Network Segmentation
allRestrict access to Avalanche management interface to trusted IPs only.
Configure firewall rules to allow only specific source IPs to TCP port 8080 (default Avalanche web interface)
Authentication Hardening
allImplement multi-factor authentication and strong password policies to reduce authentication bypass effectiveness.
🧯 If You Can't Patch
- Isolate the Avalanche server in a dedicated network segment with strict access controls.
- Monitor for unusual authentication attempts and deserialization-related errors in logs.
🔍 How to Verify
Check if Vulnerable:
Check Avalanche version in web interface or via installed program details. Version 6.3.2.3490 is vulnerable.Check Version:
Check via Avalanche web interface: Login > Help > About, or on Windows: Check installed programs list for Ivanti Avalanche version.Verify Fix Applied:
Verify version is updated to 6.3.4 or later via web interface or installed program details.📡 Detection & Monitoring
Log Indicators:
- Unusual authentication patterns, JWT token manipulation attempts, deserialization errors in application logs
Network Indicators:
- HTTP requests to JWT-related endpoints with malformed tokens, unexpected outbound connections from Avalanche service
SIEM Query:
source="avalanche_logs" AND (event_type="authentication_failure" OR message="*deserialization*" OR message="*JwtTokenUtility*")