CVE-2021-40986
📋 TL;DR
This CVE describes a remote arbitrary command execution vulnerability in Aruba ClearPass Policy Manager. Attackers can execute arbitrary commands on affected systems without authentication, potentially gaining full control. Organizations running ClearPass Policy Manager versions 6.8.x, 6.9.x, or 6.10.x without the specified patches are affected.
💻 Affected Systems
- Aruba ClearPass Policy Manager
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to execute arbitrary commands, steal sensitive data, deploy ransomware, pivot to other network segments, and maintain persistent access.
Likely Case
Attackers gain shell access to the ClearPass server, potentially compromising authentication systems, stealing credentials, and disrupting network access control services.
If Mitigated
With proper network segmentation and access controls, impact is limited to the ClearPass system itself, though credential theft and service disruption remain possible.
🎯 Exploit Status
Exploitation requires network access to the ClearPass management interface. Public exploit code exists, making this easily weaponizable.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 6.10.2, 6.9.7-HF1, or 6.8.9-HF1
Vendor Advisory: https://www.arubanetworks.com/assets/alert/ARUBA-PSA-2021-018.txt
Restart Required: Yes
Instructions:
1. Download appropriate patch from Aruba support portal. 2. Backup current configuration. 3. Apply patch via ClearPass web interface or CLI. 4. Restart ClearPass services. 5. Verify patch installation.
🔧 Temporary Workarounds
Network Access Restriction
linuxRestrict network access to ClearPass management interface to trusted IP addresses only
iptables -A INPUT -p tcp --dport 443 -s TRUSTED_IP -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP
🧯 If You Can't Patch
- Implement strict network segmentation and firewall rules to limit access to ClearPass management interface
- Deploy intrusion detection/prevention systems to monitor for exploitation attempts and block malicious traffic
🔍 How to Verify
Check if Vulnerable:
Check ClearPass version via web interface (Admin > Support > About) or CLI command 'appliance version'Check Version:
appliance versionVerify Fix Applied:
Verify version is 6.10.2, 6.9.7-HF1, or 6.8.9-HF1 or later. Test management interface functionality remains intact.📡 Detection & Monitoring
Log Indicators:
- Unusual command execution in system logs
- Unauthorized access attempts to management interface
- Suspicious process creation
Network Indicators:
- Unexpected outbound connections from ClearPass server
- Anomalous traffic patterns to/from management interface
SIEM Query:
source="clearpass" AND (event_type="command_execution" OR user="unknown" OR src_ip NOT IN [trusted_ips])