CVE-2023-32956
📋 TL;DR
This CVE describes an OS command injection vulnerability in Synology Router Manager's CGI component that allows remote attackers to execute arbitrary commands on affected routers. Attackers can potentially gain full control of the router without authentication. All Synology routers running vulnerable SRM versions are affected.
💻 Affected Systems
- Synology Router Manager (SRM)
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete router compromise allowing attackers to intercept all network traffic, install persistent malware, pivot to internal networks, and use the router as a launch point for further attacks.
Likely Case
Router takeover leading to DNS hijacking, credential theft from network traffic, and installation of backdoors for persistent access.
If Mitigated
Limited impact if router is behind firewall with restricted WAN access, though internal attackers could still exploit.
🎯 Exploit Status
The advisory mentions 'remote attackers' without specifying authentication requirements, suggesting unauthenticated exploitation is possible. No public exploit code is known at this time.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: SRM 1.2.5-8227-6 or SRM 1.3.1-9346-3 and later
Vendor Advisory: https://www.synology.com/en-global/security/advisory/Synology_SA_22_25
Restart Required: Yes
Instructions:
1. Log into Synology Router Manager web interface. 2. Navigate to Control Panel > Update & Restore. 3. Check for updates and install SRM 1.2.5-8227-6 or 1.3.1-9346-3 or later. 4. Reboot the router after installation completes.
🔧 Temporary Workarounds
Restrict WAN Access
allBlock external access to router management interface using firewall rules
Network Segmentation
allIsolate router management interface to dedicated VLAN with strict access controls
🧯 If You Can't Patch
- Disable remote management and ensure router management interface is only accessible from trusted internal networks
- Implement network monitoring for unusual outbound connections or command execution patterns from the router
🔍 How to Verify
Check if Vulnerable:
Check SRM version in Control Panel > Info Center > DSM/SRM Version. If version is earlier than 1.2.5-8227-6 (for 1.2.x branch) or earlier than 1.3.1-9346-3 (for 1.3.x branch), the system is vulnerable.Check Version:
ssh admin@router_ip 'cat /etc.defaults/VERSION' | grep 'productversion'Verify Fix Applied:
After updating, verify SRM version shows 1.2.5-8227-6 or higher, or 1.3.1-9346-3 or higher in Control Panel > Info Center.📡 Detection & Monitoring
Log Indicators:
- Unusual CGI process execution in router logs
- Unexpected command execution patterns
- Failed authentication attempts followed by successful access
Network Indicators:
- Unusual outbound connections from router
- DNS queries to suspicious domains
- Unexpected traffic patterns from router IP
SIEM Query:
source="synology-router" AND (process="cgi" OR command="*sh*" OR command="*bash*") AND result="success"