CVE-2022-43625 in DIR-1935
Summary
by MITRE • 03/29/2023
This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of D-Link DIR-1935 1.03 routers. Although authentication is required to exploit this vulnerability, the existing authentication mechanism can be bypassed. The specific flaw exists within the handling of SetStaticRouteIPv4Settings requests to the web management portal. When parsing the NetMask element, the process does not properly validate the length of user-supplied data prior to copying it to a fixed-length stack-based buffer. An attacker can leverage this vulnerability to execute code in the context of root. Was ZDI-CAN-16144.
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Analysis
by VulDB Data Team • 09/11/2026
This vulnerability represents a critical buffer overflow flaw in D-Link DIR-1935 routers running firmware version 1.03, exposing the device to remote code execution attacks. The issue stems from inadequate input validation within the web management portal's handling of SetStaticRouteIPv4Settings requests, specifically in how the NetMask element is processed. The vulnerability falls under the CWE-121 stack-based buffer overflow category, where insufficient bounds checking allows malicious data to overwrite adjacent memory locations. Attackers can bypass existing authentication mechanisms and exploit this flaw to execute arbitrary code with root privileges, effectively compromising the entire router installation.
The technical implementation of this vulnerability involves a classic stack buffer overflow scenario where user-supplied NetMask data is copied to a fixed-size stack buffer without proper length validation. This allows attackers to craft malicious input that exceeds the buffer capacity, causing memory corruption and potentially enabling code execution. The attack vector requires network adjacency, meaning adversaries must be on the same local network segment as the target device, but the authentication bypass removes the typical barrier of requiring valid credentials. This vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter and T1068 for exploit for privilege escalation.
The operational impact of this vulnerability extends beyond simple remote code execution to encompass full system compromise and potential network infiltration. Once exploited, attackers gain root-level access to the router's operating system, enabling them to modify network configurations, install persistent backdoors, monitor traffic, or use the device as a pivot point for attacking other systems within the local network. The vulnerability affects not just individual devices but potentially entire networks if multiple routers are deployed with the same firmware version. Organizations should consider this a high-priority security concern given the potential for lateral movement and persistent access to corporate networks through compromised router infrastructure.
Mitigation strategies should include immediate firmware updates from D-Link to address the buffer overflow vulnerability, along with network segmentation to limit adjacent attack surfaces. Network administrators should implement strict firewall rules to restrict access to router management interfaces and consider disabling unnecessary services. Additionally, regular security audits of network infrastructure devices are essential to identify similar vulnerabilities across the enterprise environment. The vulnerability demonstrates the importance of proper input validation and bounds checking in embedded systems, particularly those with web-based management interfaces that handle user-supplied data without adequate sanitization measures.