CVE-2018-13812 in SIMATIC HMI Comfort Panel
Summary
by MITRE
A vulnerability has been identified in SIMATIC HMI Comfort Panels 4" - 22" (All versions < V15 Update 4), SIMATIC HMI Comfort Outdoor Panels 7" & 15" (All versions < V15 Update 4), SIMATIC HMI KTP Mobile Panels KTP400F, KTP700, KTP700F, KTP900 and KTP900F (All versions < V15 Update 4), SIMATIC WinCC Runtime Advanced (All versions < V15 Update 4), SIMATIC WinCC Runtime Professional (All versions < V15 Update 4), SIMATIC WinCC (TIA Portal) (All versions < V15 Update 4), SIMATIC HMI Classic Devices (TP/MP/OP/MP Mobile Panel) (All versions). A directory traversal vulnerability could allow to download arbitrary files from the device. The security vulnerability could be exploited by an attacker with network access to the integrated web server. No user interaction and no authentication is required to exploit the vulnerability. The vulnerability impacts the confidentiality of the device. At the time of advisory publication no public exploitation of this security vulnerability was known.
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Analysis
by VulDB Data Team • 06/18/2023
This vulnerability represents a critical directory traversal flaw affecting multiple Siemens HMI and WinCC products, specifically targeting devices running versions prior to V15 Update 4. The flaw exists within the integrated web server component of these industrial control systems, allowing attackers to access arbitrary files from the device's filesystem through crafted HTTP requests. The vulnerability stems from insufficient input validation and path sanitization within the web server implementation, enabling attackers to manipulate file path parameters to navigate beyond the intended directory boundaries and retrieve sensitive information from the device.
The technical exploitation of this vulnerability occurs through network-based attacks targeting the integrated web server functionality of these industrial devices. Attackers can construct malicious URLs containing directory traversal sequences such as "../" or similar path manipulation techniques to access files outside of the web server's intended document root. This allows unauthorized access to configuration files, system logs, user credentials, and potentially sensitive operational data stored on the device. The vulnerability's severity is amplified by the fact that no authentication or user interaction is required for exploitation, making it particularly dangerous in industrial environments where such devices may be directly accessible from network segments.
The operational impact of this vulnerability extends beyond simple data exfiltration, as it compromises the confidentiality of industrial control systems and potentially exposes sensitive operational information. Attackers could access device configuration files that may contain system settings, user accounts, or network parameters that could facilitate further attacks. The vulnerability affects a broad range of Siemens industrial devices including HMI Comfort Panels, Outdoor Panels, Mobile Panels, and various WinCC runtime environments, indicating a widespread potential impact across industrial automation systems. This type of vulnerability aligns with CWE-22 Directory Traversal and can be categorized under ATT&CK technique T1083 (File and Directory Discovery) and T1566 (Phishing) when considering the potential for credential harvesting.
Organizations should immediately implement mitigation strategies including applying the relevant Siemens security updates and patches, restricting network access to these devices through firewalls and network segmentation, and monitoring for suspicious network activity targeting these systems. The vulnerability demonstrates the critical need for proper input validation and secure coding practices in industrial control systems, particularly those with web server capabilities. Network administrators should also consider implementing intrusion detection systems to monitor for directory traversal attempts and establish regular security assessments to identify similar vulnerabilities in industrial control equipment. The lack of known public exploitation at the time of advisory publication does not diminish the severity of this vulnerability, as industrial control systems often remain unpatched for extended periods, leaving them vulnerable to future exploitation attempts.