CVE-2021-40988
📋 TL;DR
This CVE describes a remote directory traversal vulnerability in Aruba ClearPass Policy Manager that allows attackers to access files outside the intended directory. Affected systems include ClearPass Policy Manager versions 6.10.x prior to 6.10.2, 6.9.x prior to 6.9.7-HF1, and 6.8.x prior to 6.8.9-HF1. The vulnerability could lead to unauthorized file access and potential information disclosure.
💻 Affected Systems
- Aruba ClearPass Policy Manager
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers could read sensitive configuration files, credentials, or system files, potentially leading to full system compromise and lateral movement within the network.
Likely Case
Unauthorized access to sensitive files containing configuration data, logs, or potentially credentials, leading to information disclosure and further attack vectors.
If Mitigated
Limited impact with proper network segmentation and access controls, potentially only exposing non-sensitive files.
🎯 Exploit Status
Directory traversal vulnerabilities typically have low exploitation complexity, though specific exploit details are not publicly available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 6.10.2, 6.9.7-HF1, 6.8.9-HF1 or later
Vendor Advisory: https://www.arubanetworks.com/assets/alert/ARUBA-PSA-2021-018.txt
Restart Required: Yes
Instructions:
1. Download the appropriate patch from Aruba support portal. 2. Backup current configuration. 3. Apply patch following Aruba's upgrade documentation. 4. Restart the ClearPass Policy Manager service. 5. Verify successful update and functionality.
🔧 Temporary Workarounds
Network Access Restriction
allRestrict network access to ClearPass Policy Manager to only trusted IP addresses and networks.
# Configure firewall rules to restrict access
# Example for iptables: iptables -A INPUT -p tcp --dport 443 -s trusted_network -j ACCEPT
# Example for Windows Firewall: New-NetFirewallRule -DisplayName "ClearPass Access" -Direction Inbound -Protocol TCP -LocalPort 443 -RemoteAddress trusted_network -Action Allow
🧯 If You Can't Patch
- Implement strict network segmentation to isolate ClearPass Policy Manager from untrusted networks
- Deploy web application firewall (WAF) with directory traversal protection rules
🔍 How to Verify
Check if Vulnerable:
Check ClearPass version via web interface (Admin > Support > About) or CLI command 'show version'Check Version:
show versionVerify Fix Applied:
Verify version is 6.10.2, 6.9.7-HF1, 6.8.9-HF1 or later, and test directory traversal attempts return proper error responses📡 Detection & Monitoring
Log Indicators:
- Unusual file access patterns in web server logs
- Multiple failed attempts to access files outside web root
- Requests containing '../' or similar traversal patterns
Network Indicators:
- HTTP requests with directory traversal sequences (../, ..\, etc.) to ClearPass endpoints
- Unusual file downloads from ClearPass web interface
SIEM Query:
source="clearpass_web_logs" AND (uri="*../*" OR uri="*..\\*" OR uri="*%2e%2e%2f*")