CVE-2020-12775
📋 TL;DR
CVE-2020-12775 is a command injection vulnerability in the Hicos citizen certificate client-side component that allows unauthenticated remote attackers to execute arbitrary system commands by exploiting improper input filtering in web URLs. This affects systems using the vulnerable Hicos software component for citizen certificate authentication. Attackers can disrupt services or gain control of affected systems.
💻 Affected Systems
- Hicos citizen certificate client-side component
📦 What is this software?
Hicos by Moica
Hicos by Moica
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to execute arbitrary commands with system privileges, install malware, exfiltrate data, or disrupt critical services.
Likely Case
Remote code execution leading to service disruption, data theft, or installation of backdoors on vulnerable systems.
If Mitigated
Limited impact with proper network segmentation, input validation, and least privilege principles in place.
🎯 Exploit Status
The vulnerability is straightforward to exploit as it involves command injection via web parameters without authentication requirements.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not explicitly specified in references, but patches were released by the vendor
Vendor Advisory: https://www.twcert.org.tw/tw/cp-132-5695-421a7-1.html
Restart Required: Yes
Instructions:
1. Check the vendor advisory for specific patch details. 2. Download and apply the official patch from the vendor. 3. Restart affected services. 4. Verify the fix is applied.
🔧 Temporary Workarounds
Input Validation Filter
allImplement strict input validation to filter special characters in command parameters
Implement web application firewall rules to block malicious patterns
Add input sanitization in application code
Network Segmentation
allIsolate systems using Hicos component from internet access
Configure firewall rules to restrict access to Hicos endpoints
Implement network segmentation
🧯 If You Can't Patch
- Implement strict web application firewall rules to block command injection patterns
- Disable or remove the Hicos citizen certificate component if not essential
🔍 How to Verify
Check if Vulnerable:
Check if Hicos citizen certificate component is installed and review version against vendor advisoryCheck Version:
Check application documentation or system registry for Hicos component versionVerify Fix Applied:
Test for command injection by attempting to inject special characters in web parameters and verify they are properly filtered📡 Detection & Monitoring
Log Indicators:
- Unusual command execution patterns
- Failed authentication attempts with special characters
- System command execution from web processes
Network Indicators:
- HTTP requests containing command injection patterns to Hicos endpoints
- Unusual outbound connections from web servers
SIEM Query:
search source="web_logs" AND (url="*rac_plugin*" AND (param="*;*" OR param="*|*" OR param="*`*"))