CVE-2020-3250
📋 TL;DR
Multiple vulnerabilities in Cisco UCS Director and UCS Director Express for Big Data REST API allow remote attackers to bypass authentication or conduct directory traversal attacks. This affects systems running vulnerable versions of these Cisco management products. Successful exploitation could lead to unauthorized access and remote code execution.
💻 Affected Systems
- Cisco UCS Director
- Cisco UCS Director Express for Big Data
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote unauthenticated attacker gains full administrative control, executes arbitrary code, and compromises the entire UCS management infrastructure.
Likely Case
Attackers bypass authentication to access sensitive configuration data, perform directory traversal to read/write files, and potentially execute commands.
If Mitigated
Limited impact with proper network segmentation, but still exposes management interface to authenticated users.
🎯 Exploit Status
Public exploit code exists on Packet Storm Security, making exploitation straightforward for attackers.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Cisco advisory for specific fixed versions
Vendor Advisory: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ucsd-mult-vulns-UNfpdW4E
Restart Required: Yes
Instructions:
1. Review Cisco advisory for affected versions. 2. Download and apply appropriate patch from Cisco. 3. Restart affected services or appliance. 4. Verify fix by testing authentication and API endpoints.
🔧 Temporary Workarounds
Network Access Control
linuxRestrict access to UCS Director REST API to trusted management networks only
iptables -A INPUT -p tcp --dport 443 -s TRUSTED_NETWORK -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP
Disable Unused REST Endpoints
allDisable unnecessary REST API endpoints if not required for operations
Consult Cisco documentation for specific endpoint configuration
🧯 If You Can't Patch
- Isolate UCS Director appliances on separate VLAN with strict firewall rules
- Implement web application firewall (WAF) with rules to detect and block authentication bypass and directory traversal attempts
🔍 How to Verify
Check if Vulnerable:
Check UCS Director version via web interface or CLI, compare against Cisco advisory affected versionsCheck Version:
ssh admin@ucs-director 'show version' or check web interface System InformationVerify Fix Applied:
Verify version is updated to patched release, test authentication bypass attempts fail, test directory traversal attempts are blocked📡 Detection & Monitoring
Log Indicators:
- Failed authentication attempts followed by successful API access
- Unusual file access patterns via REST API
- Multiple 403/401 errors followed by 200 success
Network Indicators:
- Unusual REST API traffic patterns
- Requests with ../ sequences in URLs
- Authentication bypass attempts
SIEM Query:
source="ucs-director-logs" AND (http_status=200 AND http_method=POST AND uri CONTAINS "/api/") AND NOT user IN ["admin","operator"]🔗 References
- http://packetstormsecurity.com/files/157955/Cisco-UCS-Director-Cloupia-Script-Remote-Code-Execution.html
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ucsd-mult-vulns-UNfpdW4E
- https://www.zerodayinitiative.com/advisories/ZDI-20-538/
- http://packetstormsecurity.com/files/157955/Cisco-UCS-Director-Cloupia-Script-Remote-Code-Execution.html
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ucsd-mult-vulns-UNfpdW4E
- https://www.zerodayinitiative.com/advisories/ZDI-20-538/
