CVE-2016-9362 in 750-881
Summary
by MITRE
An issue was discovered in WAGO 750-8202/PFC200 prior to FW04 (released August 2015), WAGO 750-881 prior to FW09 (released August 2016), and WAGO 0758-0874-0000-0111. By accessing a specific uniform resource locator (URL) on the web server, a malicious user is able to edit and to view settings without authenticating.
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Analysis
by VulDB Data Team • 09/17/2024
The vulnerability identified as CVE-2016-9362 represents a critical authentication bypass flaw affecting several WAGO industrial automation devices including the 750-8202/PFC200 series, 750-881 models, and specific variants of the 0758-0874-0000-0111 series. This weakness stems from improper access control implementation within the web-based management interfaces of these industrial control systems, creating a significant security risk for operational technology environments. The vulnerability specifically impacts firmware versions prior to FW04 for the 750-8202/PFC200 series and FW09 for the 750-881 series, indicating that manufacturers released patches to address this issue in their subsequent firmware updates. The flaw allows unauthenticated attackers to gain unauthorized access to system configuration settings through direct manipulation of web server URLs, fundamentally undermining the security posture of these industrial devices.
This authentication bypass vulnerability operates at the application layer and directly violates the principle of least privilege, as defined by the CWE-284 weakness category which addresses improper access control issues. The technical implementation flaw lies in the web server's URL handling mechanism where specific endpoints are accessible without proper authentication checks, enabling attackers to directly navigate to configuration pages that should require valid credentials. The vulnerability's impact extends beyond simple information disclosure as it permits both viewing and modification of critical system settings, potentially allowing malicious actors to alter industrial control parameters, modify network configurations, or disable security features. This represents a significant concern for industrial control systems where unauthorized configuration changes could lead to operational disruptions, safety hazards, or even physical damage to industrial processes.
The operational implications of this vulnerability are particularly severe in industrial environments where these devices are deployed for critical infrastructure monitoring and control. Attackers exploiting this vulnerability could potentially compromise entire industrial control networks by modifying device configurations, creating backdoors, or altering operational parameters that affect production processes. The vulnerability's accessibility through simple URL manipulation makes it particularly dangerous as it requires minimal technical expertise to exploit, increasing the attack surface for both targeted attacks and automated scanning campaigns. Organizations using these devices face potential risks including process interruption, data integrity compromise, and unauthorized access to industrial control systems that could be leveraged for broader network infiltration. The vulnerability's presence in multiple device models indicates a systemic security flaw in the manufacturers' web application security implementation, suggesting that similar issues may exist across other components of the industrial control system.
Organizations should immediately implement comprehensive mitigation strategies including firmware updates to the latest available versions that contain authentication fixes, network segmentation to isolate these devices from general network access, and implementation of additional security controls such as web application firewalls to monitor and restrict access to administrative interfaces. The vulnerability's classification as an authentication bypass issue aligns with ATT&CK technique T1078 which covers valid accounts usage, and T1566 which covers credential harvesting, making it a critical target for both defensive and offensive security teams. Regular security assessments of industrial control systems should include verification of authentication mechanisms and access controls to prevent similar vulnerabilities from being introduced in future deployments, while also ensuring that device firmware remains current with security patches. The incident underscores the importance of maintaining security hygiene in industrial environments where the consequences of authentication bypass vulnerabilities can extend far beyond simple data exposure to potentially affect physical operations and safety systems.