CVE-2023-0956 in TelWin SCADA WebInterface
Summary
by MITRE • 08/03/2023
External input could be used on TEL-STER TelWin SCADA WebInterface to construct paths to files and directories without properly neutralizing special elements within the pathname, which could allow an unauthenticated attacker to read files on the system.
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Analysis
by VulDB Data Team • 08/03/2023
The vulnerability identified as CVE-2023-0956 affects the TEL-STER TelWin SCADA WebInterface, representing a critical security flaw that exposes industrial control systems to unauthorized file access. This issue stems from insufficient input validation within the web interface component that processes external requests. The vulnerability allows attackers to manipulate file path parameters through crafted input, enabling them to traverse the filesystem and potentially access sensitive system files. The affected system operates within industrial environments where SCADA (Supervisory Control and Data Acquisition) systems manage critical infrastructure operations, making this vulnerability particularly concerning for operational technology security.
The technical implementation of this vulnerability falls under the category of path traversal attacks, specifically manifesting as a weakness in input sanitization and path resolution mechanisms. When external input is processed without proper neutralization of special characters such as directory separators or path traversal sequences, attackers can construct malicious file paths that bypass normal access controls. This flaw operates at the application layer and directly impacts the web interface's ability to validate user-supplied data before using it in file system operations. The vulnerability is classified as a path traversal issue that aligns with CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal.
The operational impact of CVE-2023-0956 extends beyond simple unauthorized file access, potentially compromising entire industrial control environments. An unauthenticated attacker could leverage this vulnerability to access configuration files, system logs, credentials, and other sensitive data stored on the SCADA server. In industrial settings, this could lead to exposure of operational parameters, control system configurations, or even facilitate more sophisticated attacks targeting the broader industrial network. The vulnerability's impact is amplified by the fact that it does not require authentication, making it particularly dangerous in environments where physical security may be inadequate. The attack surface includes not only the web interface but also any files accessible through the compromised system, potentially exposing the entire control infrastructure to compromise.
Mitigation strategies for CVE-2023-0956 should focus on implementing robust input validation and sanitization mechanisms within the TelWin SCADA WebInterface. Organizations must ensure that all user-supplied input undergoes strict validation before being used in file system operations, particularly for path resolution functions. The implementation of proper path normalization and canonicalization techniques can prevent attackers from manipulating file paths through special characters. Security controls should include input filtering that removes or escapes potentially dangerous sequences such as double dots, forward slashes, and backslashes. Additionally, implementing principle of least privilege access controls and network segmentation can limit the potential damage from exploitation. The remediation process should involve updating the affected TelWin SCADA WebInterface to a version that properly addresses the path traversal vulnerability, with patch management procedures established to ensure timely deployment of security fixes. Organizations should also conduct comprehensive vulnerability assessments of their industrial control systems to identify similar weaknesses in other components that may be vulnerable to similar attack vectors.
This vulnerability demonstrates the critical importance of security considerations in industrial control systems where traditional cybersecurity measures may not be sufficient. The ATT&CK framework categorizes this type of vulnerability under the T1083 technique for discovering file and directory permissions, and potentially T1566 for initial access through web applications. The risk assessment should consider both the immediate impact of unauthorized file access and the potential for subsequent attacks that could compromise the entire industrial control infrastructure. Regular security assessments and penetration testing of industrial environments should include evaluation of web interface components for similar path traversal vulnerabilities that could provide attackers with unauthorized access to critical system resources.