CVE-2025-7206
📋 TL;DR
A critical stack-based buffer overflow vulnerability in D-Link DIR-825 router's httpd component allows remote attackers to execute arbitrary code by manipulating the Language parameter in switch_language.cgi. This affects all users of the DIR-825 router version 2.10. The product is no longer supported by the vendor.
💻 Affected Systems
- D-Link DIR-825
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote unauthenticated attacker gains full control of the router, enabling persistent access, network traffic interception, and lateral movement into connected networks.
Likely Case
Remote code execution leading to router compromise, enabling attackers to modify configurations, intercept traffic, or use the device as a foothold for further attacks.
If Mitigated
If properly segmented and monitored, impact limited to router compromise without lateral movement to other systems.
🎯 Exploit Status
Exploit code is publicly available and targets a specific buffer overflow with straightforward exploitation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: N/A
Vendor Advisory: https://www.dlink.com/
Restart Required: No
Instructions:
No official patch available as product is end-of-life. Replace with supported hardware.
🔧 Temporary Workarounds
Disable WAN access to web interface
allBlock external access to the router's web administration interface
Configure firewall rules to block incoming traffic on port 80/443 from WAN
Network segmentation
allIsolate the router from critical internal networks
Place router in separate VLAN with restricted access to internal resources
🧯 If You Can't Patch
- Replace the router with a supported model that receives security updates
- Implement strict network monitoring and intrusion detection for the router's network segment
🔍 How to Verify
Check if Vulnerable:
Check router firmware version via web interface at http://router-ip/ or using command: telnet router-ip (if enabled) and check versionCheck Version:
Check web interface or use: curl http://router-ip/ (look for version in response headers)Verify Fix Applied:
Verify router has been replaced or isolated. No patch verification possible.📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP requests to switch_language.cgi with long Language parameters
- Multiple failed exploit attempts in web server logs
Network Indicators:
- Unusual traffic patterns to router web interface from external IPs
- Exploit payload patterns in HTTP traffic
SIEM Query:
source="router_logs" AND (uri="*switch_language.cgi*" AND (param_length>100 OR status_code=500))