CVE-2024-21887
📋 TL;DR
This is a command injection vulnerability in Ivanti Connect Secure and Policy Secure gateways that allows authenticated administrators to execute arbitrary commands on the appliance. Attackers can chain this with CVE-2023-46805 (authentication bypass) to achieve unauthenticated remote code execution. Organizations using affected Ivanti VPN appliances are at risk.
💻 Affected Systems
- Ivanti Connect Secure
- Ivanti Policy Secure
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of the VPN gateway leading to lateral movement into internal networks, data exfiltration, and persistent backdoor installation.
Likely Case
Attackers gain initial foothold via VPN appliance, then pivot to internal systems for credential harvesting and further exploitation.
If Mitigated
Limited to authenticated administrators only, reducing attack surface but still allowing privilege escalation.
🎯 Exploit Status
Multiple exploit chains combining CVE-2023-46805 and CVE-2024-21887 are publicly available and actively exploited in the wild.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Ivanti has released patches for affected versions - check vendor advisory for specific version numbers
Restart Required: Yes
Instructions:
1. Download the latest patch from Ivanti support portal. 2. Apply patch via admin interface. 3. Reboot appliance. 4. Verify patch installation and monitor for suspicious activity.
🔧 Temporary Workarounds
External Threat Protection
allBlock known exploit patterns at network perimeter
Configure WAF/IPS rules to block patterns matching CVE-2024-21887 exploitation
Access Restriction
allLimit administrative access to VPN appliances
Implement IP whitelisting for admin interfaces
Require VPN for administrative access
🧯 If You Can't Patch
- Isolate affected appliances from critical internal networks using network segmentation
- Implement strict monitoring and alerting for suspicious commands or file modifications on appliances
🔍 How to Verify
Check if Vulnerable:
Check appliance version via admin interface. If running 9.x or 22.x and not patched, assume vulnerable.Check Version:
Login to admin interface and navigate to System > Maintenance > Version InformationVerify Fix Applied:
Verify patch version in admin interface matches Ivanti's latest security release. Check for absence of exploitation indicators in logs.📡 Detection & Monitoring
Log Indicators:
- Unusual command execution in system logs
- Unexpected file creation/modification
- Authentication attempts from unusual IPs
Network Indicators:
- Suspicious HTTP requests to admin endpoints
- Outbound connections from VPN appliance to unexpected destinations
SIEM Query:
source="ivanti-vpn" AND (event_type="command_execution" OR file_path="*/.ssh/*" OR user_agent="*curl*" OR user_agent="*wget*")🔗 References
- http://packetstormsecurity.com/files/176668/Ivanti-Connect-Secure-Unauthenticated-Remote-Code-Execution.html
- https://forums.ivanti.com/s/article/CVE-2023-46805-Authentication-Bypass-CVE-2024-21887-Command-Injection-for-Ivanti-Connect-Secure-and-Ivanti-Policy-Secure-Gateways?language=en_US
- http://packetstormsecurity.com/files/176668/Ivanti-Connect-Secure-Unauthenticated-Remote-Code-Execution.html
- https://forums.ivanti.com/s/article/CVE-2023-46805-Authentication-Bypass-CVE-2024-21887-Command-Injection-for-Ivanti-Connect-Secure-and-Ivanti-Policy-Secure-Gateways?language=en_US
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2024-21887
