CVE-2021-32968 in IAW5000A
Summary
by MITRE • 04/02/2022
Two buffer overflows in the built-in web server in Moxa NPort IAW5000A-I/O Series firmware version 2.2 or earlier may allow a remote attacker to cause a denial-of-service condition.
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Analysis
by VulDB Data Team • 04/05/2022
The vulnerability identified as CVE-2021-32968 affects the Moxa NPort IAW5000A-I/O Series industrial networking equipment, specifically targeting the built-in web server component within firmware versions 2.2 and earlier. This represents a critical security flaw that exposes industrial control systems to potential remote exploitation, particularly concerning devices deployed in manufacturing environments, smart grid infrastructure, and other critical industrial applications where networked I/O capabilities are essential. The affected devices operate within the industrial internet of things ecosystem, making them attractive targets for adversaries seeking to disrupt operational technology networks.
The technical flaw manifests as two distinct buffer overflow conditions within the web server implementation that processes incoming HTTP requests. These buffer overflows occur when the web server fails to properly validate input lengths from HTTP headers or request parameters, allowing an attacker to send maliciously crafted requests that exceed allocated buffer sizes. The vulnerability stems from inadequate bounds checking mechanisms in the HTTP request parsing code, which directly violates secure coding principles outlined in CWE-121. The buffer overflow conditions can be triggered through various HTTP methods including GET, POST, and HEAD requests, making the attack surface relatively broad and accessible to remote threat actors without requiring physical access or specialized credentials.
From an operational impact perspective, successful exploitation of these buffer overflows results in a denial-of-service condition that completely disrupts the web server functionality of the affected Moxa devices. This disruption effectively renders the industrial I/O modules inaccessible through their web interface, preventing authorized personnel from monitoring or configuring the networked devices. The denial-of-service condition can persist until the device is manually rebooted or the firmware is updated, creating potential operational downtime that may affect critical industrial processes. In environments where these devices are part of larger control systems, such as SCADA networks or industrial automation systems, the disruption could cascade to affect broader operational workflows, particularly when the web interface is used for configuration management or status monitoring.
The vulnerability aligns with several ATT&CK framework techniques including T1190 for Exploit Public-Facing Application and T1499 for Endpoint Termination, as it enables remote attackers to gain control over industrial networked devices and potentially cause operational disruption. The attack vector requires no authentication and can be executed from remote locations, making it particularly dangerous in industrial environments where physical security may be less stringent than in traditional enterprise networks. Security professionals should consider this vulnerability as part of broader industrial cybersecurity assessments, particularly when evaluating the security posture of OT environments that utilize Moxa industrial networking equipment. Organizations should prioritize immediate firmware updates to address these vulnerabilities, while also implementing network segmentation and monitoring to detect potential exploitation attempts.
The affected Moxa NPort IAW5000A-I/O Series devices operate in critical infrastructure environments where reliability and security are paramount, making vulnerabilities of this nature particularly concerning. The buffer overflow conditions represent a fundamental flaw in the device's input validation mechanisms, which should be addressed through proper software development practices including input sanitization, memory bounds checking, and regular security code reviews. Organizations should also consider implementing network-based intrusion detection systems to monitor for suspicious HTTP traffic patterns that may indicate exploitation attempts against these vulnerable industrial devices. The vulnerability demonstrates the importance of maintaining current firmware versions in industrial environments and highlights the need for comprehensive vulnerability management programs that address both enterprise and operational technology systems.