CVE-2016-8721 in AWK-3131A
Summary
by MITRE
An exploitable OS Command Injection vulnerability exists in the web application 'ping' functionality of Moxa AWK-3131A Wireless Access Points running firmware 1.1. Specially crafted web form input can cause an OS Command Injection resulting in complete compromise of the vulnerable device. An attacker can exploit this vulnerability remotely.
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Analysis
by VulDB Data Team • 12/01/2022
The CVE-2016-8721 vulnerability represents a critical operating system command injection flaw in Moxa AWK-3131A Wireless Access Points, specifically affecting firmware version 1.1. This vulnerability resides within the web application's ping functionality, which is a common network diagnostic tool that allows users to test connectivity to remote hosts. The flaw stems from inadequate input validation and sanitization within the web interface, creating a pathway for malicious actors to inject arbitrary operating system commands directly into the device's underlying shell. The vulnerability is particularly concerning because it enables remote exploitation without requiring authentication, making it accessible to attackers anywhere on the network. This represents a fundamental failure in input handling that aligns with CWE-77, which specifically addresses improper neutralization of special elements used in OS commands, and reflects the broader category of command injection vulnerabilities that have been consistently ranked among the top cybersecurity risks.
The technical implementation of this vulnerability occurs when the web application processes user input through the ping form without proper sanitization of special shell metacharacters such as semicolons, ampersands, or backticks. When an attacker submits malicious input containing these characters, the web application directly incorporates them into the operating system command executed by the device's shell, thereby allowing arbitrary command execution. The attack vector is entirely remote, meaning that an attacker does not need physical access or network credentials to exploit the vulnerability. This characteristic significantly increases the attack surface and makes the device particularly vulnerable to automated exploitation campaigns. The device's response to malicious input can result in complete compromise of the access point, enabling attackers to gain full control over the device's operating system, modify configurations, access network traffic, or use the device as a pivot point for further attacks within the network. This vulnerability directly maps to attack techniques described in the MITRE ATT&CK framework under T1059.001 for command and scripting interpreter and T1021.001 for remote services, demonstrating how a single vulnerability can enable multiple attack vectors.
The operational impact of this vulnerability extends far beyond simple device compromise, as it fundamentally undermines the security posture of any network relying on Moxa AWK-3131A access points. Once compromised, the device can be used to conduct man-in-the-middle attacks, monitor network traffic, or serve as a launchpad for attacks against other networked devices. The vulnerability's remote exploitability means that attackers can target these devices from outside the network perimeter, making it particularly dangerous for organizations that do not properly segment their networks or implement robust network monitoring. Organizations using these access points may experience unauthorized access to their wireless networks, potential data exfiltration, and loss of network control. The vulnerability also highlights the importance of secure coding practices and input validation in embedded web applications, as the flaw demonstrates how a simple lack of proper input sanitization can lead to complete system compromise. Network administrators should consider the implications of this vulnerability when assessing their overall network security strategy, as it represents a potential entry point for attackers seeking to establish persistent access to wireless networks.
Mitigation strategies for CVE-2016-8721 must address both immediate remediation and long-term security improvements. The primary recommendation is to upgrade to firmware versions that address this vulnerability, as Moxa has likely released patches to correct the input validation issues. Organizations should also implement network segmentation to limit the impact of potential compromise and deploy intrusion detection systems to monitor for suspicious network activity. Additional protective measures include disabling unnecessary web services, implementing strong access controls for network management interfaces, and conducting regular security assessments of networked devices. Network monitoring should specifically look for unusual command execution patterns or attempts to access diagnostic tools that might indicate exploitation attempts. The vulnerability also underscores the need for comprehensive security testing of embedded web applications, including input validation testing, to prevent similar issues in other network equipment. Organizations should also consider implementing network access control lists to restrict access to management interfaces and ensure that only authorized personnel can interact with these critical network components. Regular vulnerability scanning and patch management processes become essential to prevent exploitation of similar vulnerabilities in other network infrastructure components.