CVE-2022-20650
📋 TL;DR
This vulnerability allows authenticated remote attackers to execute arbitrary commands with root privileges on Cisco NX-OS devices by sending crafted HTTP POST requests to the NX-API. It affects Cisco Nexus switches and MDS switches running vulnerable NX-OS software versions. The NX-API feature is disabled by default, limiting exposure.
💻 Affected Systems
- Cisco Nexus 3000 Series Switches
- Cisco Nexus 9000 Series Switches in standalone NX-OS mode
- Cisco Nexus 7000 Series Switches
- Cisco MDS 9000 Series Multilayer Switches
📦 What is this software?
Nx Os by Cisco
Nx Os by Cisco
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of affected network devices allowing attackers to reconfigure networks, intercept traffic, install persistent backdoors, or pivot to other systems.
Likely Case
Privilege escalation from authenticated user to root access on network devices, potentially leading to network disruption or data interception.
If Mitigated
Limited impact if NX-API is disabled or proper network segmentation prevents access to management interfaces.
🎯 Exploit Status
Requires authenticated access to NX-API. Exploitation involves sending crafted HTTP POST requests with command injection payloads.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: NX-OS 9.3(10), 10.2(6), 10.3(4) or later
Vendor Advisory: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nxos-nxapi-cmdinject-ULukNMZ2
Restart Required: Yes
Instructions:
1. Check current NX-OS version with 'show version'. 2. Download appropriate fixed version from Cisco Software Center. 3. Follow Cisco's NX-OS upgrade procedures for your specific platform. 4. Reboot device after upgrade.
🔧 Temporary Workarounds
Disable NX-API
allCompletely disable the NX-API feature to prevent exploitation
configure terminal
no feature nxapi
copy running-config startup-config
Restrict NX-API Access
allLimit NX-API access to trusted management networks using ACLs
configure terminal
ip access-list NXAPI-ACL
permit ip <trusted-network> any
deny ip any any
interface mgmt0
ip access-group NXAPI-ACL in
copy running-config startup-config
🧯 If You Can't Patch
- Disable NX-API feature immediately if not required
- Implement strict network segmentation to isolate management interfaces from untrusted networks
🔍 How to Verify
Check if Vulnerable:
Check if NX-API is enabled: 'show feature | include nxapi'. Check NX-OS version: 'show version | include NXOS'Check Version:
show version | include NXOSVerify Fix Applied:
Verify NX-OS version is 9.3(10), 10.2(6), 10.3(4) or later: 'show version | include NXOS'📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP POST requests to NX-API endpoints
- Commands executed via NX-API with unusual parameters
- Authentication logs showing access to NX-API from unexpected sources
Network Indicators:
- HTTP traffic to NX-API port (typically 80/443) with unusual payload patterns
- Command injection patterns in HTTP POST requests
SIEM Query:
source="nxos-logs" AND (http_method="POST" AND uri="/api/*" AND (payload CONTAINS "$" OR payload CONTAINS "|" OR payload CONTAINS ";"))