CVE-2025-4347: D-Link Router Buffer Overflow Vulnerability Leading to Potential System Compromise

Overview

A critical vulnerability has been discovered in D-Link DIR-600L routers up to version 2.07B01. This vulnerability, identified as CVE-2025-4347, has been rated as a high-severity threat with a CVSS score of 8.8. It affects the function formWlSiteSurvey and could potentially lead to system compromise or data leakage. The vulnerability is particularly concerning as it affects products that are no longer supported by the maintainer, leaving these devices exposed without a forthcoming patch from the vendor.

Vulnerability Summary

CVE ID: CVE-2025-4347
Severity: Critical (CVSS: 8.8)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: Potential system compromise or data leakage

Affected Products

Product | Affected Versions

D-Link DIR-600L | Up to 2.07B01

How the Exploit Works

The vulnerability resides in the formWlSiteSurvey function of D-Link DIR-600L routers. By manipulating the ‘host’ argument in this function, an attacker can cause a buffer overflow condition. Buffer overflows are dangerous as they can potentially allow an attacker to execute arbitrary code on the target system or cause the system to crash. This vulnerability can be exploited remotely, which increases the risk associated with this flaw.

Conceptual Example Code

This is a hypothetical example of how an attacker might exploit this vulnerability. In this scenario, the attacker sends a maliciously crafted HTTP request that causes a buffer overflow condition.

POST /formWlSiteSurvey HTTP/1.1
Host: vulnerable-router
Content-Type: application/json
{ "host": "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA..." }

In this example, the “A” string is longer than the buffer allocated for the ‘host’ parameter. The excess data overflows into adjacent memory, potentially leading to code execution or a system crash.

Mitigation

Given the high risk associated with this vulnerability, it is advised to apply a patch from the vendor, if available. If a patch is not available due to the end of product support, it may be necessary to consider other mitigation strategies such as using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) to detect and block exploit attempts. However, these are only temporary measures and it is highly recommended to replace unsupported devices with ones that receive regular security updates from the vendor.