CVE-2023-48842
📋 TL;DR
This CVE describes a command injection vulnerability in D-Link Go-RT-AC750 routers that allows attackers to execute arbitrary commands via the service parameter in hedwig.cgi. Attackers can gain full control of affected devices, potentially compromising network security. All users of D-Link Go-RT-AC750 routers with the vulnerable firmware are affected.
💻 Affected Systems
- D-Link Go-RT-AC750
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device takeover leading to persistent backdoor installation, network traffic interception, lateral movement to other devices, and participation in botnets.
Likely Case
Remote code execution allowing attackers to modify router settings, intercept traffic, or use the device as a pivot point for further attacks.
If Mitigated
Limited impact if device is behind firewall with restricted WAN access and proper network segmentation.
🎯 Exploit Status
Command injection vulnerabilities are typically easy to exploit with publicly available tools and techniques.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: Yes
Instructions:
1. Check D-Link support site for firmware updates. 2. Download latest firmware. 3. Access router admin interface. 4. Navigate to firmware update section. 5. Upload and apply new firmware. 6. Reboot router.
🔧 Temporary Workarounds
Disable WAN access to admin interface
allPrevent external access to the vulnerable CGI endpoint
Access router admin > Security > Remote Management > Disable
Block access to hedwig.cgi
linuxUse firewall rules to block access to the vulnerable endpoint
iptables -A INPUT -p tcp --dport 80 -m string --string "hedwig.cgi" --algo bm -j DROP
🧯 If You Can't Patch
- Isolate affected routers in separate VLAN with strict firewall rules
- Implement network monitoring for unusual outbound connections from routers
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface under System > FirmwareCheck Version:
curl -s http://router-ip/hedwig.cgi | grep -i versionVerify Fix Applied:
Verify firmware version is updated beyond revA_v101b03📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to hedwig.cgi with service parameter containing shell metacharacters
- Multiple failed login attempts followed by successful access
Network Indicators:
- Unusual outbound connections from router IP
- Traffic to known malicious IPs from router
SIEM Query:
source="router-logs" AND uri="*hedwig.cgi*" AND (service="*;*" OR service="*|*" OR service="*`*" OR service="*$(*")