CVE-2024-20477
📋 TL;DR
This vulnerability allows authenticated low-privileged attackers to upload or delete files on Cisco NDFC devices via a specific REST API endpoint with missing authorization controls. Only systems running vulnerable Cisco NDFC versions are affected, requiring attacker authentication but not administrative privileges.
💻 Affected Systems
- Cisco Nexus Dashboard Fabric Controller (NDFC)
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attacker could upload malicious files to execute arbitrary code or delete critical system files, potentially leading to service disruption or complete system compromise.
Likely Case
Attackers could upload configuration files to modify system behavior or delete operational files to cause service degradation.
If Mitigated
With proper network segmentation and API access controls, impact would be limited to isolated container operations without affecting core system functionality.
🎯 Exploit Status
Exploitation requires authenticated access and knowledge of the vulnerable API endpoint. No public exploit code available at advisory publication.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 12.2.2e and later
Vendor Advisory: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ndhs-uaapi-Jh4V6zpN
Restart Required: Yes
Instructions:
1. Download Cisco NDFC version 12.2.2e or later from Cisco Software Center. 2. Backup current configuration. 3. Apply the update following Cisco NDFC upgrade procedures. 4. Restart the NDFC appliance.
🔧 Temporary Workarounds
Restrict API Access
allImplement network access controls to limit access to the vulnerable REST API endpoint from untrusted networks.
Enhanced Authentication
allImplement multi-factor authentication for all API access and review user privilege assignments.
🧯 If You Can't Patch
- Implement strict network segmentation to isolate NDFC management interfaces from general user networks
- Enable detailed API access logging and implement real-time monitoring for suspicious file upload/deletion activities
🔍 How to Verify
Check if Vulnerable:
Check NDFC version via web interface or CLI. Versions below 12.2.2e are vulnerable.Check Version:
show version (in NDFC CLI) or check System > About in web interfaceVerify Fix Applied:
Verify NDFC version is 12.2.2e or later and test API endpoint authorization controls.📡 Detection & Monitoring
Log Indicators:
- Unusual file uploads via REST API
- File deletion operations from non-admin users
- Multiple failed authorization attempts followed by successful API calls
Network Indicators:
- HTTP POST/PUT/DELETE requests to the vulnerable API endpoint from unexpected sources
- Unusual traffic patterns to NDFC REST API
SIEM Query:
source="ndfc" AND (http_method="POST" OR http_method="PUT" OR http_method="DELETE") AND uri_path="/api/vulnerable-endpoint" AND user_role!="admin"