CVE-2024-36136
📋 TL;DR
An off-by-one error in WLInfoRailService in Ivanti Avalanche allows remote unauthenticated attackers to crash the service, causing denial of service. This affects Ivanti Avalanche 6.3.1 installations, potentially disrupting mobile device management operations.
💻 Affected Systems
- Ivanti Avalanche
📦 What is this software?
Avalanche by Ivanti
Avalanche by Ivanti
Avalanche by Ivanti
Avalanche by Ivanti
Avalanche by Ivanti
Avalanche by Ivanti
Avalanche by Ivanti
Avalanche by Ivanti
Avalanche by Ivanti
Avalanche by Ivanti
Avalanche by Ivanti
Avalanche by Ivanti
Avalanche by Ivanti
Avalanche by Ivanti
Avalanche by Ivanti
Avalanche by Ivanti
Avalanche by Ivanti
Avalanche by Ivanti
Avalanche by Ivanti
Avalanche by Ivanti
⚠️ Risk & Real-World Impact
Worst Case
Complete service outage of Avalanche management server, disrupting all mobile device management operations until service is manually restarted.
Likely Case
Service crash requiring manual restart, causing temporary disruption to device management and reporting functions.
If Mitigated
Minimal impact with proper network segmentation and monitoring allowing quick detection and recovery.
🎯 Exploit Status
Off-by-one errors typically require minimal exploitation complexity, especially with remote unauthenticated access.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 6.4.4
Vendor Advisory: https://forums.ivanti.com/s/article/Security-Advisory-Ivanti-Avalanche-6-4-4-CVE-2024-38652-CVE-2024-38653-CVE-2024-36136-CVE-2024-37399-CVE-2024-37373
Restart Required: Yes
Instructions:
1. Download Ivanti Avalanche 6.4.4 from the Ivanti portal. 2. Backup current configuration and database. 3. Run the installer to upgrade from 6.3.1 to 6.4.4. 4. Restart the Avalanche service and verify functionality.
🔧 Temporary Workarounds
Network Access Restriction
allRestrict network access to the Avalanche server to only trusted management networks
Service Monitoring and Auto-restart
windowsConfigure monitoring to detect service crashes and automatically restart the WLInfoRailService
🧯 If You Can't Patch
- Implement strict network segmentation to isolate Avalanche server from untrusted networks
- Deploy intrusion detection/prevention systems to monitor for exploitation attempts and block malicious traffic
🔍 How to Verify
Check if Vulnerable:
Check Avalanche version in the web interface under Help > About, or check installed programs in Windows Control Panel for 'Ivanti Avalanche 6.3.1'Check Version:
wmic product where "name like 'Ivanti Avalanche%'" get versionVerify Fix Applied:
Verify version shows 6.4.4 or higher in the Avalanche web interface, and test that WLInfoRailService remains running under normal load📡 Detection & Monitoring
Log Indicators:
- WLInfoRailService crash events in Windows Event Logs
- Avalanche service restart events
- Unexpected termination of wlinforail.exe process
Network Indicators:
- Unusual traffic patterns to Avalanche server port 1777
- Multiple connection attempts followed by service unavailability
SIEM Query:
EventID=7034 OR EventID=1000 AND Source='WLInfoRailService' OR ProcessName='wlinforail.exe'