CVE-2021-34748
📋 TL;DR
This vulnerability allows authenticated remote attackers to execute arbitrary commands with root privileges on Cisco Intersight Virtual Appliance by exploiting insufficient input validation in the web management interface. It affects organizations using Cisco Intersight Virtual Appliance for infrastructure management. Attackers need valid credentials to exploit this command injection flaw.
💻 Affected Systems
- Cisco Intersight Virtual Appliance
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with root-level access, allowing data theft, lateral movement, persistence installation, and service disruption.
Likely Case
Unauthorized command execution leading to configuration changes, data exfiltration, or deployment of malware/backdoors.
If Mitigated
Limited impact due to network segmentation, strong authentication controls, and monitoring preventing successful exploitation.
🎯 Exploit Status
Exploitation requires valid credentials but is straightforward once authenticated. No public exploit code available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.0.9-292 and later
Vendor Advisory: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ucsi2-command-inject-CGyC8y2R
Restart Required: Yes
Instructions:
1. Download Intersight Virtual Appliance version 1.0.9-292 or later from Cisco. 2. Deploy the updated virtual appliance. 3. Migrate configuration from old appliance. 4. Verify functionality and decommission old appliance.
🔧 Temporary Workarounds
Restrict Management Interface Access
linuxLimit access to the web management interface to trusted IP addresses only using firewall rules.
iptables -A INPUT -p tcp --dport 443 -s TRUSTED_IP -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP
🧯 If You Can't Patch
- Implement strict network segmentation to isolate Intersight Virtual Appliance from critical systems
- Enforce strong authentication policies and monitor for suspicious login attempts
🔍 How to Verify
Check if Vulnerable:
Check Intersight Virtual Appliance version via web interface or SSH: cat /etc/intersight/versionCheck Version:
cat /etc/intersight/versionVerify Fix Applied:
Verify version is 1.0.9-292 or later and test command injection attempts are blocked📡 Detection & Monitoring
Log Indicators:
- Unusual command execution in system logs
- Multiple failed authentication attempts followed by successful login
- Web interface requests with suspicious parameters containing shell metacharacters
Network Indicators:
- Unusual outbound connections from Intersight appliance
- Traffic patterns suggesting data exfiltration
SIEM Query:
source="intersight" AND (event_type="command_execution" OR http_request CONTAINS "|" OR http_request CONTAINS ";" OR http_request CONTAINS "`")