CVE-2022-36974
📋 TL;DR
This vulnerability in Ivanti Avalanche allows authenticated remote attackers to bypass authentication and execute arbitrary code via insecure deserialization in the Web File Server service. Attackers can gain code execution with service account privileges. Affects 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
Full system compromise with attacker gaining service account privileges, lateral movement within network, data exfiltration, and persistence establishment.
Likely Case
Remote code execution leading to service disruption, data theft, and potential ransomware deployment.
If Mitigated
Limited impact with proper network segmentation, authentication controls, and monitoring detecting exploitation attempts.
🎯 Exploit Status
Authentication bypass exists, making exploitation easier than typical authenticated vulnerabilities. ZDI advisory suggests exploit is straightforward.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 6.3.4 and later
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 or later from official vendor site. 2. Backup current configuration. 3. Install update following vendor documentation. 4. Restart all Avalanche services.
🔧 Temporary Workarounds
Network Segmentation
allRestrict network access to Web File Server service to only trusted IPs/networks.
Use firewall rules to block inbound traffic to port 8080 (default Web File Server port) from untrusted networks
Service Disablement
windowsTemporarily disable Web File Server service if not required for operations.
sc stop "Ivanti Avalanche Web File Server"
sc config "Ivanti Avalanche Web File Server" start= disabled
🧯 If You Can't Patch
- Implement strict network access controls to limit who can reach the Web File Server service
- Enable detailed logging and monitoring for suspicious deserialization attempts and authentication bypass patterns
🔍 How to Verify
Check if Vulnerable:
Check Avalanche version via Control Panel > Programs > Programs and Features, or run 'wmic product get name,version' and look for Ivanti Avalanche version 6.3.2.3490 or earlier.Check Version:
wmic product where "name like '%Avalanche%'" get name,versionVerify Fix Applied:
Verify version is 6.3.4 or later using same method, and ensure Web File Server service is running the updated version.📡 Detection & Monitoring
Log Indicators:
- Unusual authentication attempts to Web File Server
- Deserialization errors in application logs
- Suspicious process creation from Avalanche service account
Network Indicators:
- Unusual traffic patterns to Web File Server port (default 8080)
- Malformed serialization payloads in network traffic
SIEM Query:
source="avalanche_logs" AND (event_type="authentication_bypass" OR event_type="deserialization_error")