CVE-2026-111548 in NPort W2150A-W4
Summary
by MITRE • 10/27/2026
A stack-based buffer overflow vulnerability exists in the web management interface of affected Moxa wireless device servers. An authenticated remote attacker with low privileges could exploit insufficient bounds checking of user-supplied input, causing the web management service to become unresponsive. Restoring the service requires power cycling the affected device, while other device functions remain operational.
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Analysis
by VulDB Data Team • 10/27/2026
The identified vulnerability represents a critical security flaw within the embedded software architecture of specific Moxa wireless device servers, specifically located in their web-based management interface. This stack-based buffer overflow arises from insufficient bounds checking when processing user-supplied input data sent to the server's administrative services. In typical networked environments, such interfaces are designed to accept configuration parameters or status queries from authorized users; however, the underlying code fails to validate the length of incoming strings against the allocated memory buffers on the call stack. This architectural weakness allows an attacker who has already obtained low-privilege authentication credentials to inject oversized data payloads that exceed the buffer limits. When the application attempts to process this malformed input, it overwrites adjacent memory locations on the stack, corrupting critical control structures such as return addresses or saved frame pointers.
From a technical perspective, this flaw aligns with Common Weakness Enumeration identifier CWE-121, which describes a stack-based buffer overflow resulting from copying user-controlled data without proper size validation. The exploitation mechanism does not necessarily require achieving arbitrary code execution in the traditional sense of gaining root access to the operating system kernel. Instead, the immediate consequence is the corruption of the application's internal state or thread context, leading directly to a denial-of-service condition. When the web management service encounters this memory corruption during request processing, it enters an unstable state and becomes unresponsive. This effectively locks out administrators from managing the device through its primary graphical interface, disrupting operational visibility and control capabilities that are essential for maintaining network infrastructure integrity.
The operational impact of this vulnerability is significant due to the persistence required to restore service functionality. Unlike many software crashes where a simple process restart might suffice, recovering from this specific stack-based overflow necessitates power cycling the physical device server. This requirement introduces substantial downtime and logistical overhead, particularly in remote or hard-to-reach industrial deployments typical for Moxa hardware. While other core functions of the device continue to operate normally, meaning data acquisition and basic connectivity remain intact, the loss of administrative access hinders troubleshooting, configuration updates, and security monitoring. Furthermore, because exploitation requires authenticated access with low privileges, it highlights a risk associated with shared or compromised user accounts that possess minimal but sufficient permissions to interact with the web interface.
In terms of threat modeling, this vulnerability maps closely to MITRE ATT&CK technique T1498, specifically Network Denial of Service via resource exhaustion or service disruption through application layer attacks. The attacker leverages valid credentials to trigger a denial-of-service event that degrades the availability component of the CIA triad for management functions. To mitigate this risk, immediate remediation should focus on applying vendor-provided firmware updates that patch the input validation logic within the web server module. Until patches are available, network segmentation strategies can be employed to restrict access to the management interface exclusively from trusted administrative subnets using firewalls or VLAN isolation. Additionally, enforcing strict password policies and multi-factor authentication for all accounts with even low-level privileges reduces the attack surface by ensuring that only verified personnel can attempt interactions with the vulnerable component, thereby raising the barrier for potential exploitation attempts.