CVE-2017-16720 in WebAccess
Summary
by MITRE
A Path Traversal issue was discovered in WebAccess versions prior to 8.3. An attacker has access to files within the directory structure of the target device.
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Analysis
by VulDB Data Team • 12/19/2019
The vulnerability identified as CVE-2017-16720 represents a critical path traversal flaw in Wonderware WebAccess software versions prior to 8.3. This weakness allows remote attackers to access files and directories that are outside the intended scope of the web application, potentially exposing sensitive system resources. The vulnerability stems from insufficient input validation and improper handling of file paths within the web interface, creating an avenue for unauthorized data access and system enumeration.
This path traversal vulnerability operates at the application layer and can be classified under CWE-22, which specifically addresses improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal. The flaw enables attackers to manipulate file path parameters through crafted input, allowing them to navigate through the file system hierarchy and access files that should remain protected. The vulnerability affects the web server component of WebAccess, which typically serves as the interface for monitoring and controlling industrial processes.
The operational impact of this vulnerability extends beyond simple information disclosure, as it can provide attackers with access to critical system files, configuration data, and potentially sensitive operational information. Attackers can leverage this weakness to gain insights into the target environment, identify system configurations, and potentially extract credentials or other sensitive data stored within the application's directory structure. The vulnerability poses significant risk to industrial control systems where WebAccess is deployed, as it could enable adversaries to compromise the integrity and availability of critical infrastructure monitoring systems.
From an attack perspective, this vulnerability aligns with ATT&CK technique T1083, which involves discovering system information through the use of commands that can enumerate files and directories. The flaw can be exploited without authentication in many cases, making it particularly dangerous for industrial environments where security controls may be less stringent. Organizations using WebAccess versions prior to 8.3 are at risk of unauthorized access to process control data, system logs, and configuration files that could be used to plan more sophisticated attacks against the industrial control systems.
The recommended mitigation strategy involves upgrading to WebAccess version 8.3 or later, which includes proper input validation and path sanitization mechanisms. Additionally, implementing network segmentation, restricting access to the web interface through firewall rules, and applying the principle of least privilege can significantly reduce the attack surface. System administrators should also conduct thorough file system audits to identify any unauthorized access that may have occurred due to this vulnerability, while monitoring for suspicious file access patterns that could indicate exploitation attempts.