CVE-2025-3785: Critical Buffer Overflow Vulnerability in D-Link DWR-M961

Overview

In today’s digital era, the security of our routers and network devices is as important as the security of our personal computers. A recently discovered vulnerability, CVE-2025-3785, in D-Link’s DWR-M961 router software has highlighted this issue. This vulnerability, identified as a critical stack-based buffer overflow, has a severe impact on the security and integrity of D-Link routers, specifically version 1.1.36. The vulnerability can lead to potential system compromise or data leakage, posing a great risk to both individual users and businesses alike.

Vulnerability Summary

CVE ID: CVE-2025-3785
Severity: Critical, CVSS Score of 8.8
Attack Vector: Remote
Privileges Required: None
User Interaction: Not required
Impact: Potential system compromise or data leakage

Affected Products

Product | Affected Versions

D-Link DWR-M961 | up to version 1.1.36

How the Exploit Works

The vulnerability resides in the unknown code of the file /boafrm/formStaticDHCP of the component Authorization Interface. An attacker can exploit this vulnerability by manipulating the Hostname argument, leading to a stack-based buffer overflow. The attack can be initiated remotely without the need for user interaction or special privileges. Once the buffer overflow occurs, the attacker can execute arbitrary code, potentially compromising the system or leaking sensitive data.

Conceptual Example Code

The following is a conceptual example of how this vulnerability might be exploited. In this example, a malicious HTTP request is sent to the vulnerable router, manipulating the Hostname argument to trigger the buffer overflow.

POST /boafrm/formStaticDHCP HTTP/1.1
Host: vulnerable-router.com
Content-Type: application/json
{ "Hostname": "A".repeat(5000) } // Oversized Hostname argument to trigger buffer overflow

Recommendations and Mitigation Measures

The safest and most effective way to address this issue is to upgrade the affected component to version 1.1.49, which has been patched by the vendor to fix this vulnerability. If upgrading is not immediately feasible, using a Web Application Firewall (WAF) or an Intrusion Detection System (IDS) can serve as temporary mitigation. As always, maintaining a robust and updated security system is crucial in protecting against such vulnerabilities.