CVE-2025-29044
📋 TL;DR
A buffer overflow vulnerability in Netgear R61 router firmware allows remote attackers to execute arbitrary code by sending specially crafted QUERY_STRING values. This affects Netgear R61 router users running vulnerable firmware versions. Attackers can exploit this without authentication to gain full control of affected devices.
💻 Affected Systems
- Netgear R61 router
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise 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 devices are behind firewalls with strict ingress filtering and network segmentation.
🎯 Exploit Status
Public proof-of-concept code is available, making exploitation straightforward for attackers with basic skills.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: Yes
Instructions:
1. Check Netgear support site for firmware updates 2. Download latest firmware 3. Access router admin interface 4. Upload and apply firmware update 5. Reboot router
🔧 Temporary Workarounds
Network Segmentation
allPlace router behind firewall with strict ingress filtering to block external exploitation attempts
Access Control
allRestrict administrative access to trusted IP addresses only
🧯 If You Can't Patch
- Replace affected router with updated model or different vendor
- Implement strict network monitoring and anomaly detection for router traffic
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface. If version is V1.0.1.28, device is vulnerable.Check Version:
Check router web interface or use: curl -s http://router-ip/currentsetting.htm | grep firmwareVerify Fix Applied:
Verify firmware version has been updated to a version later than V1.0.1.28📡 Detection & Monitoring
Log Indicators:
- Unusual QUERY_STRING parameter values in web logs
- Multiple failed exploitation attempts
- Unexpected process execution
Network Indicators:
- Unusual HTTP requests to router CGI endpoints
- Traffic patterns indicating command and control communication
SIEM Query:
source="router_logs" AND (QUERY_STRING="*overflow*" OR QUERY_STRING="*shell*" OR QUERY_STRING="*cmd*")🔗 References
- https://gist.github.com/xyqer1/09fe6488a6655776c8c5d33e630a0f2a
- https://github.com/xyqer1/Netgear-R6100-cgiMain-QUERY_STRING-StackOverflow?tab=readme-ov-file
- https://gist.github.com/xyqer1/09fe6488a6655776c8c5d33e630a0f2a
- https://github.com/xyqer1/Netgear-R6100-cgiMain-QUERY_STRING-StackOverflow?tab=readme-ov-file
