CVE-2020-8963
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary operating system commands on affected TimeTools network time servers by injecting shell metacharacters into specific CGI parameters. Attackers can gain full system control without authentication. Organizations using TimeTools SC, SR, or T series devices with vulnerable firmware are affected.
💻 Affected Systems
- TimeTools SC7105
- SC9205
- SC9705
- SR7110
- SR9210
- SR9750
- SR9850
- T100
- T300
- T550
📦 What is this software?
Sc7105 Firmware by Timetoolsltd
Sc9205 Firmware by Timetoolsltd
Sc9705 Firmware by Timetoolsltd
Sr7110 Firmware by Timetoolsltd
Sr9210 Firmware by Timetoolsltd
Sr9750 Firmware by Timetoolsltd
Sr9850 Firmware by Timetoolsltd
T100 Firmware by Timetoolsltd
T300 Firmware by Timetoolsltd
T550 Firmware by Timetoolsltd
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of the network time server, allowing attackers to install persistent backdoors, pivot to internal networks, disrupt time synchronization across the organization, and use the device as a launch point for further attacks.
Likely Case
Remote code execution leading to device takeover, configuration modification, credential theft, and potential lateral movement within the network.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering and network segmentation prevents lateral movement from compromised devices.
🎯 Exploit Status
Public exploit details are available in blog posts showing how to inject commands via t3.cgi parameters. The attack requires no authentication and minimal technical skill.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: No official vendor advisory found
Restart Required: No
Instructions:
No official patch is available. Check with TimeTools for firmware updates or consider replacing devices if no fix is provided.
🔧 Temporary Workarounds
Network Access Control
allRestrict network access to TimeTools devices using firewall rules to allow only trusted management IPs.
Disable Web Interface
allIf possible, disable the web interface and use alternative management methods (CLI, serial console).
🧯 If You Can't Patch
- Isolate affected devices in a dedicated VLAN with strict firewall rules preventing outbound connections except for NTP traffic.
- Implement network monitoring and intrusion detection specifically for traffic to/from TimeTools devices to detect exploitation attempts.
🔍 How to Verify
Check if Vulnerable:
Check device firmware version via web interface or CLI. If running affected versions and web interface is accessible, assume vulnerable.Check Version:
Check via web interface at /t3.cgi or use SNMP if configured. No universal CLI command available.Verify Fix Applied:
Verify firmware has been updated to a version not listed in affected versions. Test web interface for command injection by attempting safe commands (e.g., 'id' or 'whoami') via t3.cgi parameters.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /t3.cgi with shell metacharacters (;, |, &, $, etc.) in srmodel or srtime parameters
- Unexpected processes or commands executed on the device
Network Indicators:
- HTTP requests containing command injection patterns to TimeTools devices
- Unusual outbound connections from TimeTools devices
SIEM Query:
http.url:*t3.cgi* AND (http.param:*srmodel* OR http.param:*srtime*) AND (http.param:*;* OR http.param:*|* OR http.param:*&* OR http.param:*`*)