CVE-2017-17888 in Anti-Web
Summary
by MITRE
cgi-bin/write.cgi in Anti-Web through 3.8.7, as used on NetBiter / HMS, Ouman EH-net, Alliance System WS100 --> AWU 500, Sauter ERW100F001, Carlo Gavazzi SIU-DLG, AEDILIS SMART-1, SYXTHSENSE WebBiter, ABB SREA, and ASCON DY WebServer devices, allows remote authenticated users to execute arbitrary OS commands via crafted multipart/form-data content, a different vulnerability than CVE-2017-9097.
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Analysis
by VulDB Data Team • 12/18/2019
This vulnerability exists in the cgi-bin/write.cgi component of Anti-Web software versions through 3.8.7, which is deployed on various industrial and embedded network devices including NetBiter, HMS, Ouman EH-net, Alliance System WS100, Sauter ERW100F001, Carlo Gavazzi SIU-DLG, AEDILIS SMART-1, SYXTHSENSE WebBiter, ABB SREA, and ASCON DY WebServer devices. The flaw represents a critical command injection vulnerability that allows authenticated remote attackers to execute arbitrary operating system commands on the affected devices. The vulnerability specifically manifests when the application processes crafted multipart/form-data content through the write.cgi script, enabling attackers to bypass authentication mechanisms and gain unauthorized control over the underlying operating system. This represents a significant security risk for industrial control systems and embedded devices that rely on web interfaces for configuration and management purposes.
The technical implementation of this vulnerability stems from improper input validation within the write.cgi script, which fails to properly sanitize user-supplied data before processing it as part of command execution. When an authenticated user submits malicious multipart/form-data content, the application directly incorporates this data into system commands without adequate sanitization or escaping mechanisms. This design flaw allows attackers to inject command delimiters and additional shell commands that get executed with the privileges of the web application process. The vulnerability is classified as a command injection issue under CWE-77, which specifically addresses situations where user-supplied data is used in system calls without proper validation or sanitization. The affected devices typically run embedded operating systems with limited security controls, making them particularly vulnerable to such exploitation techniques.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it enables attackers to gain full control over the affected industrial devices and potentially compromise entire network segments. Attackers can leverage this vulnerability to install backdoors, modify device configurations, access sensitive operational data, or even disrupt critical industrial processes. The fact that this vulnerability affects multiple device manufacturers and models indicates a widespread exposure across various industrial control systems, including those used in energy, manufacturing, and infrastructure sectors. Organizations deploying these devices face significant risks including potential operational disruptions, data breaches, and compromise of critical infrastructure. The vulnerability's presence in devices that may be located in physically secure environments but accessible via network connections creates additional attack surface considerations. This type of vulnerability aligns with ATT&CK technique T1059.001 for Command and Scripting Interpreter, where adversaries use legitimate system tools to execute malicious commands.
Mitigation strategies for this vulnerability require immediate patching of affected Anti-Web software versions to 3.8.8 or later, which contains the necessary input validation fixes. Organizations should also implement network segmentation to isolate these industrial devices from general network access, enforce strict access controls and authentication mechanisms, and monitor network traffic for suspicious command execution patterns. Additional protective measures include disabling unnecessary web interfaces, implementing network access controls using firewalls, and conducting regular security assessments of industrial control systems. The vulnerability highlights the importance of secure coding practices and proper input validation in embedded systems, particularly those handling user-supplied data in industrial environments. Organizations should also consider implementing intrusion detection systems specifically designed to monitor for command injection attempts and other exploitation patterns in industrial control networks. Given the critical nature of these devices and their potential impact on operational technology systems, comprehensive security postures must be maintained through regular vulnerability assessments and patch management processes.