CVE-2020-25036
📋 TL;DR
This vulnerability allows authenticated remote attackers to escape the restricted administration shell CLI on UCOPIA Wi-Fi appliances and gain full admin shell access. Attackers can execute arbitrary commands with admin privileges, potentially compromising the entire appliance. Organizations using UCOPIA Wi-Fi appliances version 6.0.5 are affected.
💻 Affected Systems
- UCOPIA Wi-Fi appliances
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full compromise of the UCOPIA appliance leading to network pivoting, credential theft, deployment of persistent backdoors, and complete control over Wi-Fi infrastructure.
Likely Case
Attackers gain admin shell access to modify configurations, intercept traffic, deploy malware, or use the appliance as a foothold into the network.
If Mitigated
Limited impact if proper network segmentation, strong authentication, and monitoring are in place, though the appliance remains vulnerable to authenticated attackers.
🎯 Exploit Status
Exploitation involves using the 'less' command to escape the restricted shell. Public details are available in the referenced blog posts.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: https://ucopia.com/en/solutions/product-line-wifi/
Restart Required: No
Instructions:
Check UCOPIA vendor advisory for updates. Upgrade to a patched version if available. If no patch exists, apply workarounds immediately.
🔧 Temporary Workarounds
Restrict 'less' command access
linuxRemove or restrict execution of the 'less' command from the restricted administration shell to prevent escape.
Modify shell configuration to block 'less' command execution
Implement strict access controls
allLimit administrative access to trusted IPs and enforce strong authentication.
Configure firewall rules and use multi-factor authentication
🧯 If You Can't Patch
- Isolate UCOPIA appliances in a dedicated network segment with strict inbound/outbound firewall rules.
- Monitor all administrative access and shell command execution for suspicious activity.
🔍 How to Verify
Check if Vulnerable:
Check if running UCOPIA Wi-Fi appliance version 6.0.5. Attempt to use 'less' command from authenticated admin CLI to see if shell escape is possible.Check Version:
Check appliance web interface or CLI for version information (specific command varies by appliance).Verify Fix Applied:
Verify that 'less' command no longer allows shell escape and that admin shell access is properly restricted.📡 Detection & Monitoring
Log Indicators:
- Unusual 'less' command usage in admin logs
- Shell escape attempts
- Unexpected admin shell access
Network Indicators:
- Suspicious outbound connections from UCOPIA appliance
- Unexpected administrative access patterns
SIEM Query:
Search for 'less' command execution in UCOPIA admin logs followed by shell commands.