CVE-2026-2925: D-Link DWR-M960 Buffer Overflow Flaw

CVE-2026-2925 Overview

A stack-based buffer overflow vulnerability has been identified in the D-Link DWR-M960 wireless router running firmware version 1.01.07. The vulnerability exists in the function sub_42B5A0 within the Bridge VLAN Configuration Endpoint located at /boafrm/formBridgeVlan. An attacker can exploit this vulnerability by manipulating the submit-url argument, leading to a stack-based buffer overflow condition. The vulnerability can be exploited remotely and a public exploit is now available, significantly increasing the risk profile for affected devices.

Critical Impact

Remote attackers with low privileges can exploit this stack-based buffer overflow to potentially achieve code execution on vulnerable D-Link DWR-M960 routers, compromising network infrastructure integrity.

Affected Products

• D-Link DWR-M960 Firmware version 1.01.07
• D-Link DWR-M960 Hardware revision B1
• dlink dwr-m960_firmware

Discovery Timeline

• 2026-02-22 - CVE-2026-2925 published to NVD
• 2026-02-23 - Last updated in NVD database

Technical Details for CVE-2026-2925

Vulnerability Analysis

This vulnerability is classified under CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer). The flaw resides in the web management interface of the D-Link DWR-M960 router, specifically within the Bridge VLAN configuration handling mechanism. When processing VLAN configuration requests, the sub_42B5A0 function fails to properly validate the length of user-supplied input in the submit-url parameter before copying it to a fixed-size stack buffer.

The vulnerability is remotely exploitable over the network and requires only low-level privileges to trigger. No user interaction is required for successful exploitation. The impact spans confidentiality, integrity, and availability, as successful exploitation could allow an attacker to execute arbitrary code with elevated privileges on the affected device.

Root Cause

The root cause of this vulnerability lies in inadequate input validation and bounds checking within the sub_42B5A0 function. The firmware fails to verify that user-supplied data in the submit-url argument fits within the allocated stack buffer before performing memory copy operations. This allows an attacker to supply an oversized input that overwrites adjacent stack memory, including return addresses and saved registers, potentially leading to control flow hijacking.

Attack Vector

The attack vector is network-based, targeting the web management interface of the router. An attacker can craft malicious HTTP requests to the /boafrm/formBridgeVlan endpoint with an excessively long submit-url parameter value. Since the vulnerability requires only low privileges, an authenticated user with basic access to the router's web interface could potentially exploit this flaw.

The exploitation process involves:

1. Gaining access to the router's web management interface
2. Crafting a POST request to /boafrm/formBridgeVlan with a maliciously crafted submit-url parameter
3. The oversized input triggers the buffer overflow in sub_42B5A0
4. Overwritten stack data may redirect execution flow to attacker-controlled code

Technical details regarding the vulnerability mechanism can be found in the GitHub Issue Discussion and VulDB CTI Entry #347272.

Detection Methods for CVE-2026-2925

Indicators of Compromise

• Unusual HTTP POST requests to /boafrm/formBridgeVlan with abnormally long submit-url parameter values
• Router crashes, reboots, or unresponsive web management interface
• Unexpected changes to VLAN configuration or network settings
• Anomalous outbound connections from the router to unknown external IP addresses

Detection Strategies

• Monitor HTTP traffic to the router's web interface for requests containing oversized parameters in VLAN configuration endpoints
• Deploy network intrusion detection rules to identify buffer overflow exploitation patterns targeting D-Link devices
• Implement anomaly detection for router behavior, including unexpected restarts or configuration changes
• Review router access logs for authentication events followed by requests to /boafrm/formBridgeVlan

Monitoring Recommendations

• Enable logging on the D-Link DWR-M960 and forward logs to a centralized SIEM for analysis
• Set up alerts for multiple failed authentication attempts followed by successful logins
• Monitor for firmware integrity changes or unauthorized configuration modifications
• Implement network segmentation to isolate IoT and network infrastructure devices from general user traffic

How to Mitigate CVE-2026-2925

Immediate Actions Required

• Restrict access to the router's web management interface to trusted IP addresses only
• Disable remote management access if not required for operations
• Implement strong authentication credentials and change default passwords
• Place the affected router behind a firewall with strict ingress filtering
• Monitor for firmware updates from D-Link and apply patches immediately when available

Patch Information

At the time of publication, no official patch information has been released by D-Link for this vulnerability. Organizations should monitor the D-Link Homepage for security advisories and firmware updates. Reference materials are available through VulDB #347272 and VulDB Submission #754497.

Workarounds

• Disable the web management interface and manage the router via console access only if feasible
• Implement network access control lists (ACLs) to restrict which hosts can communicate with the router's management interface
• Consider deploying a web application firewall (WAF) to filter malicious requests targeting the vulnerable endpoint
• If possible, isolate the affected device on a separate network segment with limited connectivity

Network administrators should configure access restrictions using their firewall or router access control settings to limit management interface access to specific trusted IP addresses or network ranges. Additionally, consider implementing 802.1X authentication for network access control to reduce the attack surface.