CVE-2016-2331
📋 TL;DR
This vulnerability allows remote attackers to gain unauthorized access to SysLINK SL-1000 M2M gateway devices through the web interface using default credentials. Affected systems are all SysLINK SL-1000 devices running firmware versions before 01A.8. This is a critical authentication bypass vulnerability.
💻 Affected Systems
- SysLINK SL-1000 Machine-to-Machine (M2M) Modular Gateway
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of the M2M gateway allowing attackers to intercept, modify, or disrupt industrial control system communications, potentially leading to physical system manipulation or operational shutdown.
Likely Case
Unauthorized access to device configuration, network traffic monitoring, credential harvesting, and potential lateral movement to connected industrial systems.
If Mitigated
Limited impact if strong network segmentation, access controls, and monitoring are in place to detect authentication attempts.
🎯 Exploit Status
Exploitation requires only knowledge of default credentials and network access to the web interface.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Firmware 01A.8 or later
Vendor Advisory: http://www.kb.cert.org/vuls/id/822980
Restart Required: Yes
Instructions:
1. Download firmware 01A.8 or later from vendor. 2. Backup current configuration. 3. Upload firmware via web interface. 4. Reboot device. 5. Verify firmware version. 6. Change default credentials.
🔧 Temporary Workarounds
Change Default Credentials
allImmediately change the default administrator password to a strong, unique password.
Access web interface > Administration > User Management > Change Password
Network Segmentation
allIsolate SysLINK devices in separate VLANs with strict firewall rules limiting access to management interfaces.
🧯 If You Can't Patch
- Implement strict network access controls to limit web interface access to authorized IP addresses only
- Enable logging and monitoring for authentication attempts and configuration changes
🔍 How to Verify
Check if Vulnerable:
Check firmware version via web interface: Login > System > Firmware Information. If version is below 01A.8, device is vulnerable.Check Version:
Check via web interface or SSH: show version (if SSH enabled)Verify Fix Applied:
Verify firmware version is 01A.8 or higher and test that default credentials no longer work.📡 Detection & Monitoring
Log Indicators:
- Failed login attempts followed by successful login
- Configuration changes from unknown IPs
- Multiple authentication attempts from single source
Network Indicators:
- HTTP/HTTPS traffic to device management interface from unexpected sources
- Unusual outbound connections from device
SIEM Query:
source="syslink" AND (event_type="authentication" AND result="success") AND user="admin"