CVE-2024-51003 – Multiple Netgear router models contain stack ov... (How to Fix)

Q: What is the severity of CVE-2024-51003?

CVE-2024-51003 has a CVSS score of 5.7 (MEDIUM). Multiple Netgear router models contain stack overflow vulnerabilities in the ap_mode.cgi component via DNS parameters. Attackers can exploit these vulnerabilities by sending crafted POST requests to cause Denial of Service (DoS). Users of affected Netgear router models with vulnerable firmware versions are impacted.

📋 TL;DR

Multiple Netgear router models contain stack overflow vulnerabilities in the ap_mode.cgi component via DNS parameters. Attackers can exploit these vulnerabilities by sending crafted POST requests to cause Denial of Service (DoS). Users of affected Netgear router models with vulnerable firmware versions are impacted.

💻 Affected Systems

Products:

Netgear R8500
Netgear XR300
Netgear R7000P
Netgear R6400 v2

Versions: R8500 v1.0.2.160, XR300 v1.0.3.78, R7000P v1.3.3.154, R6400 v2 1.0.4.128

Operating Systems: Router firmware

Default Config Vulnerable: ⚠️ Yes

Notes: Vulnerability exists in the web interface component handling AP mode configuration.

📦 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 or reboots, causing temporary network outage until device restarts.

🟢

If Mitigated

Limited impact with proper network segmentation and monitoring, though service disruption still occurs.

🌐 Internet-Facing: HIGH

🏢 Internal Only: MEDIUM

🎯 Exploit Status

Public PoC: ⚠️ Yes

Weaponized: LIKELY

Unauthenticated Exploit: ⚠️ Yes

Complexity: LOW

Exploit requires sending crafted POST request to vulnerable endpoint; no authentication needed.

🛠️ 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 firmware updates. 2. Download latest firmware from Netgear support site. 3. Upload firmware via router web interface. 4. Wait for installation and reboot.

🔧 Temporary Workarounds

Disable remote management

all

Prevents external exploitation by disabling web interface access from WAN

Network segmentation

all

Isolate router management interface to trusted network segment

🧯 If You Can't Patch

Implement strict firewall rules to block external access to router web interface
Monitor router logs for unusual POST requests to ap_mode.cgi endpoint

🔍 How to Verify

Check if Vulnerable:

Check router firmware version in web interface under Advanced > Administration > Router Update

Check Version:

Check via router web interface; no CLI command available

Verify Fix Applied:

Verify firmware version is newer than affected versions listed

📡 Detection & Monitoring

Log Indicators:

Unusual POST requests to /ap_mode.cgi
Router crash/reboot events
Large DNS parameter values in requests

Network Indicators:

HTTP POST requests with oversized apmode_dns1_pri or apmode_dns1_sec parameters

SIEM Query:

http.method:POST AND http.uri:"/ap_mode.cgi" AND (http.param:"apmode_dns1_pri" OR http.param:"apmode_dns1_sec")

📊 Metadata

CVE ID: CVE-2024-51003

CVSS v3 Score: 5.7 (MEDIUM)

CVSS Vector: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CWE: CWE-120

Published: November 5, 2024

Last Updated: May 7, 2025

🔗 References

https://github.com/wudipjq/my_vuln/blob/main/Netgear4/vuln_49/49.md Broken Link
https://www.netgear.com/about/security/ Vendor Advisory

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