CVE-2024-23532
📋 TL;DR
An authenticated remote attacker can exploit an out-of-bounds read vulnerability in the WLAvalancheService component of Ivanti Avalanche to cause denial of service. In some conditions, this may also lead to remote code execution. Affected users are those running Ivanti Avalanche versions before 6.4.3 with the vulnerable service exposed.
💻 Affected Systems
- Ivanti Avalanche
📦 What is this software?
Avalanche by Ivanti
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to full system compromise and potential lateral movement within the network.
Likely Case
Denial of service attacks disrupting the Avalanche service and managed devices.
If Mitigated
Limited impact if network segmentation and authentication controls restrict access to the service.
🎯 Exploit Status
Exploitation requires authenticated access, which may involve valid credentials or session tokens.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 6.4.3
Vendor Advisory: https://forums.ivanti.com/s/article/Avalanche-6-4-3-Security-Hardening-and-CVEs-addressed?language=en_US
Restart Required: Yes
Instructions:
1. Download Ivanti Avalanche version 6.4.3 from the official vendor portal. 2. Backup current configuration and data. 3. Install the update following Ivanti's upgrade guide. 4. Restart the Avalanche server to apply changes.
🔧 Temporary Workarounds
Restrict Network Access
linuxLimit access to the WLAvalancheService to trusted IP addresses only using firewall rules.
iptables -A INPUT -p tcp --dport <port> -s <trusted_ip> -j ACCEPT
iptables -A INPUT -p tcp --dport <port> -j DROP
Disable Unused Service
linuxIf the WLAvalancheService is not required, disable it to reduce attack surface.
systemctl stop WLAvalancheService
systemctl disable WLAvalancheService
🧯 If You Can't Patch
- Implement strict network segmentation to isolate the Avalanche server from untrusted networks.
- Enforce strong authentication policies and monitor for unusual access patterns to the service.
🔍 How to Verify
Check if Vulnerable:
Check the Avalanche server version via the web interface or command line; if version is below 6.4.3, it is vulnerable.Check Version:
On Windows: wmic product where name='Ivanti Avalanche' get version. On Linux: dpkg -l | grep avalanche or rpm -qa | grep avalanche.Verify Fix Applied:
After patching, confirm the version is 6.4.3 or higher and test service functionality.📡 Detection & Monitoring
Log Indicators:
- Unusual authentication attempts to WLAvalancheService
- Service crash logs or error messages indicating out-of-bounds reads
Network Indicators:
- Suspicious traffic patterns to the Avalanche service port (default 1777/TCP)
- Anomalous outbound connections from the server post-exploit
SIEM Query:
source='avalanche_logs' AND (event_id='5000' OR message LIKE '%out-of-bounds%' OR message LIKE '%denial of service%')