CVE-2025-4349: Critical Command Injection Vulnerability in D-Link DIR-600L Routers

Overview

The vulnerability CVE-2025-4349 is a critical security flaw found in D-Link DIR-600L routers up to version 2.07B01. This flaw affects the function formSysCmd and allows for command injection through host argument manipulation. The severity of this vulnerability is heightened due to its ability to be exploited remotely, potentially leading to system compromise or data leakage. As the affected products are no longer supported by the maintainer, it is crucial for users to be aware of this vulnerability and apply the necessary mitigation strategies.

Vulnerability Summary

CVE ID: CVE-2025-4349
Severity: Critical (CVSS score 8.8)
Attack Vector: Remote
Privileges Required: None
User Interaction: None
Impact: System compromise or data leakage

Affected Products

Product | Affected Versions

D-Link DIR-600L | All versions up to 2.07B01

How the Exploit Works

The vulnerability exists in the formSysCmd function, where the host argument can be manipulated. This manipulation allows the execution of arbitrary system commands, leading to command injection. As this can be initiated remotely, it provides an attacker with the ability to compromise the system or leak data.

Conceptual Example Code

Below is a conceptual example of how the vulnerability might be exploited. This is represented as a HTTP request where an attacker sends a POST request with a malicious payload to the vulnerable endpoint.

POST /formSysCmd HTTP/1.1
Host: target.example.com
Content-Type: application/json
{ "host": "; rm -rf /" }

In this example, the host argument is manipulated to execute the ‘rm -rf /’ command, which deletes all files on the system. This highlights the severity and potential damage of this vulnerability.

Mitigation Guidance

As the products affected by this vulnerability are no longer supported by the maintainer (D-Link), the most effective mitigation strategy would be to apply a vendor patch. In the absence of a patch, using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can provide temporary mitigation by detecting and preventing attempts to exploit this vulnerability. Furthermore, it is advisable to replace unsupported products with more secure and supported alternatives when possible.