CVE-2026-90699 in DWR-M920
Summary
by MITRE • 09/14/2026
A weakness has been identified in D-Link DWR-M920 1.1.7. This issue affects the function sub_41E60C of the file /boafrm/formPinManageSetup. This manipulation of the argument newPin causes os command injection. The attack can be initiated remotely. The exploit has been made available to the public and could be used for attacks.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 09/14/2026
The D-Link DWR-M920 router, specifically firmware version 1.1.7, contains a critical security vulnerability within its web management interface that allows for remote code execution via command injection. This flaw is located in the sub_41E60C function associated with the formPinManageSetup endpoint of the boafrm CGI binary. The boa server is commonly used by embedded devices to handle HTTP requests from administrative interfaces, and vulnerabilities within this layer often provide attackers with a direct path to compromise the underlying operating system. In this specific instance, the vulnerability stems from improper input validation when processing the newPin argument submitted through the PIN management setup form.
The technical nature of this flaw is classified as OS command injection, which corresponds to CWE-78 in the Common Weakness Enumeration standard. This type of weakness occurs when an application constructs a system-level command using user-supplied input without sufficiently neutralizing special elements that could modify the intended command structure. In the context of the DWR-M920, the newPin parameter is likely passed directly to a shell interpreter or a function like system() or popen() without adequate sanitization. An attacker can inject malicious shell commands by appending them to the PIN value using standard injection characters such as semicolons, ampersands, or pipes. Because this input vector is accessible through the web interface, it represents an unauthenticated attack surface if the router does not require prior authentication for this specific form, or a low-privilege authenticated vulnerability if some level of access is required to reach the PIN management page.
The operational impact of this vulnerability is severe due to its remote exploitability and the high privileges typically held by processes running embedded web servers. Since the boa server often runs with root-level permissions on many D-Link devices, successfully exploiting this command injection allows an attacker to execute arbitrary commands as the root user. This grants full control over the device, enabling the installation of persistent malware such as botnet agents like Mirai or Hajime, credential harvesting from connected clients, network traffic interception, and use of the router as a pivot point for further attacks against internal network assets. The fact that public exploits are available significantly lowers the barrier to entry for attackers, increasing the likelihood of automated scanning and widespread compromise across vulnerable deployments.
This vulnerability aligns with several tactics in the MITRE ATT&CK framework, particularly T1059 Command and Scripting Interpreter under Execution techniques, where adversaries use system commands to run malicious code. It also relates to T1190 Exploit Public-Facing Application, as the flaw is located in a service exposed to potential remote attackers via the internet or local network interfaces. The presence of public exploits indicates that threat actors are actively leveraging this weakness for large-scale campaigns targeting IoT infrastructure.
Mitigation strategies should prioritize immediate firmware updates if D-Link has released a patched version addressing CWE-78 in the boafrm component. If an update is not immediately available, administrators can implement network-level controls such as firewall rules to restrict access to the router's management interface only from trusted IP addresses or VLANs. Additionally, disabling remote administration features and changing default credentials are essential baseline security measures that reduce the attack surface. For organizations relying on this device, continuous monitoring for anomalous outbound traffic patterns indicative of botnet activity is recommended until the vulnerability can be fully remediated through software patching.