CVE-2023-51619
📋 TL;DR
This vulnerability allows network-adjacent attackers with valid credentials to execute arbitrary code as root on D-Link DIR-X3260 routers. The flaw exists in the prog.cgi binary that handles HNAP requests, where improper input validation leads to a stack-based buffer overflow. Attackers on the same network can exploit this to gain complete control of affected routers.
💻 Affected Systems
- D-Link DIR-X3260
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete router compromise allowing attacker to intercept all network traffic, install persistent malware, pivot to internal networks, and use router as attack platform.
Likely Case
Router takeover leading to DNS hijacking, credential theft from network traffic, and deployment of malware to connected devices.
If Mitigated
Limited impact if strong network segmentation, authentication controls, and monitoring are in place to detect exploitation attempts.
🎯 Exploit Status
Exploitation requires authentication but the vulnerability is in a critical component with root privileges. ZDI has published technical details.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Firmware 1.10B07
Vendor Advisory: https://supportannouncement.us.dlink.com/announcement/publication.aspx?name=SAP10365
Restart Required: Yes
Instructions:
1. Download firmware 1.10B07 from D-Link support site. 2. Log into router web interface. 3. Navigate to System Tools > Firmware Upgrade. 4. Upload the firmware file. 5. Wait for upgrade to complete and router to reboot.
🔧 Temporary Workarounds
Disable remote management
allPrevent external access to router web interface
Restrict management interface access
allLimit which IP addresses can access router management
🧯 If You Can't Patch
- Isolate router on separate VLAN with strict access controls
- Implement network monitoring for unusual HNAP requests to prog.cgi
🔍 How to Verify
Check if Vulnerable:
Check firmware version in router web interface under System Status. If version is earlier than 1.10B07, the device is vulnerable.Check Version:
Check via web interface or SSH if enabled: cat /proc/version or show version in CLIVerify Fix Applied:
Confirm firmware version shows 1.10B07 or later in System Status page.📡 Detection & Monitoring
Log Indicators:
- Unusual HNAP POST requests to /prog.cgi
- Multiple failed authentication attempts followed by successful login and prog.cgi access
- Router logs showing unexpected reboots or configuration changes
Network Indicators:
- Unusual outbound connections from router
- DNS queries to suspicious domains from router
- Traffic patterns suggesting router compromise
SIEM Query:
source="router_logs" AND (uri="/prog.cgi" OR uri="/HNAP1/") AND method="POST" AND size>1024