CVE-2026-2927 Overview
A stack-based buffer overflow vulnerability has been identified in D-Link DWR-M960 firmware version 1.01.07. This vulnerability affects the function sub_462590 within the file /boafrm/formOpMode of the Operation Mode Configuration Endpoint. The manipulation of the submit-url argument enables attackers to trigger a stack-based buffer overflow condition, potentially leading to arbitrary code execution on the affected device.
Critical Impact
Remote attackers can exploit this vulnerability to execute arbitrary code or cause denial of service on D-Link DWR-M960 routers by sending specially crafted requests to the Operation Mode Configuration Endpoint.
Affected Products
- D-Link DWR-M960 Firmware version 1.01.07
- D-Link DWR-M960 Hardware revision B1
- D-Link DWR-M960 4G LTE Router
Discovery Timeline
- 2026-02-22 - CVE-2026-2927 published to NVD
- 2026-02-23 - Last updated in NVD database
Technical Details for CVE-2026-2927
Vulnerability Analysis
This vulnerability is classified as CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer). The affected component is the Operation Mode Configuration Endpoint accessible via /boafrm/formOpMode. When processing the submit-url parameter, the sub_462590 function fails to properly validate the length of user-supplied input before copying it to a fixed-size stack buffer.
The network-accessible nature of this vulnerability means attackers can potentially exploit it remotely without physical access to the device. Once triggered, the buffer overflow can overwrite critical stack data including return addresses, enabling attackers to redirect program execution to malicious code.
Root Cause
The root cause lies in the lack of proper bounds checking when handling the submit-url parameter in the sub_462590 function. The firmware does not validate that user-supplied input fits within the allocated stack buffer before performing copy operations. This is a classic stack-based buffer overflow scenario where excessive input data overwrites adjacent memory locations on the call stack.
Attack Vector
The attack can be initiated remotely over the network by sending a specially crafted HTTP request to the /boafrm/formOpMode endpoint. An attacker with low privileges (authenticated access) can manipulate the submit-url argument with an oversized payload to trigger the buffer overflow. The exploit has been publicly disclosed, increasing the risk of active exploitation attempts.
The vulnerability requires network access to the router's management interface, typically accessible on the local network or potentially exposed to the internet if the administration interface is misconfigured.
Detection Methods for CVE-2026-2927
Indicators of Compromise
- Unusual HTTP POST requests to /boafrm/formOpMode containing abnormally long submit-url parameters
- Device crashes, reboots, or unexpected behavior following web interface access
- Suspicious network traffic patterns targeting D-Link router management ports
- Log entries showing malformed requests to the Operation Mode Configuration Endpoint
Detection Strategies
- Monitor HTTP traffic for requests to /boafrm/formOpMode with submit-url parameters exceeding normal length thresholds
- Implement intrusion detection rules to identify buffer overflow attack patterns targeting D-Link devices
- Review router access logs for unauthorized or unusual administrative access attempts
- Deploy network-based anomaly detection to identify exploitation attempts
Monitoring Recommendations
- Enable logging on all D-Link DWR-M960 devices and forward logs to a centralized SIEM solution
- Configure alerts for multiple failed authentication attempts or unusual administrative activity
- Monitor for firmware integrity changes that may indicate successful compromise
- Regularly audit devices for unexpected configuration changes
How to Mitigate CVE-2026-2927
Immediate Actions Required
- Restrict access to the router's web management interface to trusted networks only
- Disable remote management features if not required for operations
- Implement network segmentation to isolate vulnerable devices from untrusted networks
- Monitor D-Link security advisories for firmware updates addressing this vulnerability
Patch Information
At the time of this publication, no official patch has been released by D-Link for this vulnerability. Organizations should monitor the D-Link Security Page for security updates and firmware releases. Additional technical details and vulnerability tracking information are available through VulDB #347274 and the GitHub Issue Report.
Workarounds
- Configure firewall rules to block external access to the router's management interface
- Use VPN or jump host access for remote administration instead of exposing the web interface
- Implement access control lists (ACLs) to restrict management interface access to specific IP addresses
- Consider replacing end-of-life devices with supported hardware if patches are not forthcoming
# Example firewall rule to restrict management access (adjust for your environment)
# Block external access to router management port
iptables -A INPUT -p tcp --dport 80 -s ! 192.168.1.0/24 -j DROP
iptables -A INPUT -p tcp --dport 443 -s ! 192.168.1.0/24 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
