CVE-2023-51615
📋 TL;DR
This vulnerability allows network-adjacent attackers with authentication to execute arbitrary code as root on D-Link DIR-X3260 routers. The flaw exists in the prog.cgi binary's handling of HNAP requests, where improper validation of PSK strings leads to stack-based buffer overflow. Only authenticated attackers on the local network can exploit this vulnerability.
💻 Affected Systems
- D-Link DIR-X3260
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete router compromise with root-level remote code execution, allowing attacker to intercept all network traffic, modify router settings, install persistent malware, and pivot to other devices on the network.
Likely Case
Router takeover by authenticated malicious insider or compromised device on the local network, leading to network traffic interception and potential credential theft.
If Mitigated
Limited impact due to authentication requirement and network adjacency needed, with proper network segmentation preventing lateral movement.
🎯 Exploit Status
Exploitation requires authentication but is straightforward once authenticated. The vulnerability is well-documented in ZDI advisory ZDI-24-035.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Firmware version 1.10B04
Vendor Advisory: https://supportannouncement.us.dlink.com/announcement/publication.aspx?name=SAP10365
Restart Required: Yes
Instructions:
1. Download firmware version 1.10B04 from D-Link support site. 2. Log into router admin 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 QuickVPN
allDisable the vulnerable QuickVPN feature if not required
Restrict Admin Access
allLimit admin interface access to specific trusted IP addresses only
🧯 If You Can't Patch
- Segment router management interface to dedicated VLAN accessible only by authorized administrators
- Implement strong authentication policies and regularly rotate admin credentials
🔍 How to Verify
Check if Vulnerable:
Check current firmware version in router admin interface under System Status. If version is earlier than 1.10B04, the device is vulnerable.Check Version:
Check via web interface: System Status > Firmware VersionVerify Fix Applied:
Verify firmware version shows 1.10B04 or later in System Status page after upgrade.📡 Detection & Monitoring
Log Indicators:
- Multiple failed authentication attempts followed by successful login and HNAP requests to prog.cgi with SetQuickVPNSettings action
- Unusual POST requests to /HNAP1/ with large PSK parameter values
Network Indicators:
- HTTP/HTTPS traffic to router on ports 80/443 with HNAP SOAP requests containing SetQuickVPNSettings
- Unusual outbound connections from router after successful exploitation
SIEM Query:
source="router-logs" AND (uri="/HNAP1/" AND method="POST" AND request_body CONTAINS "SetQuickVPNSettings")