CVE-2024-51020
📋 TL;DR
This vulnerability in Netgear R7000P routers allows attackers to trigger a stack overflow via the apn parameter in usbISP_detail_edit.cgi, leading to Denial of Service (DoS). Attackers can exploit this by sending a crafted POST request. Only Netgear R7000P routers running firmware version 1.3.3.154 are affected.
💻 Affected Systems
- Netgear R7000P
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete router crash requiring physical reboot, potentially disrupting all network connectivity for connected devices.
Likely Case
Router becomes unresponsive, requiring reboot to restore functionality, causing temporary network outage.
If Mitigated
Minimal impact if router is behind firewall with restricted web interface access.
🎯 Exploit Status
Simple POST request with oversized apn parameter; no authentication required based on CWE-120 buffer overflow pattern.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: https://www.netgear.com/about/security/
Restart Required: Yes
Instructions:
1. Check Netgear security advisory for patch availability. 2. If patch exists, download from Netgear support site. 3. Upload firmware via router web interface. 4. Reboot router after installation.
🔧 Temporary Workarounds
Disable Remote Management
allPrevent external access to router web interface
Login to router admin > Advanced > Administration > Remote Management > Disable
Block usbISP_detail_edit.cgi Access
linuxRestrict access to vulnerable endpoint via firewall rules
iptables -A INPUT -p tcp --dport 80 -m string --string "usbISP_detail_edit.cgi" --algo bm -j DROP
iptables -A INPUT -p tcp --dport 443 -m string --string "usbISP_detail_edit.cgi" --algo bm -j DROP
🧯 If You Can't Patch
- Isolate router on separate network segment with strict firewall rules
- Implement network monitoring for abnormal POST requests to usbISP_detail_edit.cgi
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface: Advanced > Administration > Router Update > Current VersionCheck Version:
curl -s http://router-ip/currentsetting.htm | grep firmwareVerify Fix Applied:
Verify firmware version is newer than v1.3.3.154 and test usbISP_detail_edit.cgi endpoint with safe payload📡 Detection & Monitoring
Log Indicators:
- Repeated POST requests to usbISP_detail_edit.cgi with large apn parameter
- Router crash/reboot logs
Network Indicators:
- Unusual POST requests to router IP on port 80/443 containing usbISP_detail_edit.cgi
- Sudden loss of router responsiveness
SIEM Query:
source="router.log" AND "POST" AND "usbISP_detail_edit.cgi" AND (apn.length>100 OR "overflow")