CVE-2024-23534
📋 TL;DR
This vulnerability allows authenticated remote attackers to upload malicious files to Ivanti Avalanche web components, leading to arbitrary command execution with SYSTEM privileges. It affects Ivanti Avalanche versions before 6.4.3. Attackers must have valid credentials to exploit this vulnerability.
💻 Affected Systems
- Ivanti Avalanche
📦 What is this software?
Avalanche by Ivanti
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with SYSTEM privileges, allowing attackers to install malware, steal data, pivot to other systems, or disrupt operations.
Likely Case
Attackers gain persistent access to the system, deploy ransomware or backdoors, and potentially compromise the entire network.
If Mitigated
Limited impact if proper file upload restrictions and privilege separation are in place, though authenticated attackers could still cause damage.
🎯 Exploit Status
Exploitation requires authenticated access but is straightforward once credentials are obtained. The CVSS score of 8.8 indicates high exploitability.
🛠️ 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 6.4.3 from the official Ivanti portal. 2. Backup current configuration and data. 3. Run the installer to upgrade to version 6.4.3. 4. Restart the Avalanche server and verify the update.
🔧 Temporary Workarounds
Restrict File Upload Types
windowsConfigure the web server to only allow specific file types and validate file extensions server-side.
Implement Web Application Firewall Rules
allDeploy WAF rules to block suspicious file upload patterns and restrict upload functionality.
🧯 If You Can't Patch
- Restrict network access to the Avalanche web interface using firewall rules to only trusted IP addresses.
- Implement strong authentication controls, multi-factor authentication, and monitor for suspicious login attempts.
🔍 How to Verify
Check if Vulnerable:
Check the Avalanche version via the web interface admin panel or by examining installed programs in Windows.Check Version:
In Avalanche web interface: Navigate to Help > About, or check Windows Programs and Features for version.Verify Fix Applied:
Verify the version number shows 6.4.3 or higher in the Avalanche admin interface.📡 Detection & Monitoring
Log Indicators:
- Unusual file uploads in web server logs
- Multiple failed authentication attempts followed by successful login and file upload
- Execution of unexpected system commands
Network Indicators:
- HTTP POST requests with file uploads to Avalanche endpoints from unusual sources
- Outbound connections from Avalanche server to unknown IPs post-upload
SIEM Query:
source="avalanche_logs" AND (event="file_upload" AND file_extension NOT IN ("jpg","png","pdf")) OR (process="cmd.exe" OR process="powershell.exe" FROM host="avalanche_server")