CVE-2020-3140
📋 TL;DR
An unauthenticated remote attacker can gain administrative privileges on Cisco Prime License Manager by exploiting insufficient input validation in the web management interface. This affects all systems running vulnerable versions of Cisco PLM software. Attackers need a valid username but no password to achieve complete system compromise.
💻 Affected Systems
- Cisco Prime License Manager
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system takeover with administrative privileges, allowing installation of persistent backdoors, data exfiltration, and lateral movement to connected systems.
Likely Case
Attackers gain administrative control over the PLM system, potentially compromising license management and using the system as a foothold for further attacks.
If Mitigated
With proper network segmentation and access controls, impact is limited to the PLM system itself, though administrative compromise remains severe.
🎯 Exploit Status
Exploitation requires only a valid username (no password needed) and web interface access. The CVSS 9.8 score indicates trivial exploitation with high impact.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Cisco Prime License Manager 11.5(1)SU2 and later
Vendor Advisory: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-cisco-prime-priv-esc-HyhwdzBA
Restart Required: Yes
Instructions:
1. Download the patched version from Cisco's software download center. 2. Backup current configuration. 3. Install the update following Cisco's upgrade documentation. 4. Restart the PLM service or system as required.
🔧 Temporary Workarounds
Restrict Web Interface Access
allLimit access to the PLM web management interface using network controls
Disable Unused Accounts
allRemove or disable any unnecessary user accounts to reduce attack surface
🧯 If You Can't Patch
- Implement strict network segmentation to isolate PLM systems from critical infrastructure
- Deploy web application firewall (WAF) rules to block suspicious requests to the management interface
🔍 How to Verify
Check if Vulnerable:
Check the PLM version via the web interface (Help > About) or CLI command 'show version'Check Version:
show versionVerify Fix Applied:
Verify version is 11.5(1)SU2 or later and test that unauthorized privilege escalation attempts fail📡 Detection & Monitoring
Log Indicators:
- Failed authentication attempts followed by successful administrative actions
- Unusual privilege escalation patterns in audit logs
Network Indicators:
- HTTP requests to PLM web interface with privilege escalation patterns
- Unusual administrative traffic from unexpected sources
SIEM Query:
source="plm_logs" AND (event_type="privilege_escalation" OR (auth_failure AND subsequent_admin_action))