CVE-2018-13813 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). The webserver of affected HMI devices may allow URL redirections to untrusted websites. An attacker must trick a valid user who is authenticated to the device into clicking on a malicious link to exploit the vulnerability. 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 web application security flaw affecting Siemens HMI devices and runtime environments that fall under the broader category of industrial control systems. The issue manifests as an insecure direct object reference vulnerability that allows unauthorized redirection to external websites through the webserver component of these devices. The affected products span multiple HMI panel types including Comfort Panels, Outdoor Panels, Mobile Panels, and various WinCC runtime environments, all operating below version 15 Update 4. This vulnerability is particularly concerning because it leverages user trust and requires minimal attacker interaction beyond social engineering to potentially compromise system integrity.
The technical implementation of this vulnerability stems from improper validation of user-supplied input within the webserver component of these industrial devices. When users navigate to certain web interfaces, the system fails to properly sanitize or validate URL parameters that could lead to redirection to malicious external sites. This weakness creates an attack vector where an attacker can craft specially formatted links that, when clicked by an authenticated user, will redirect them to untrusted domains. The vulnerability operates at the application layer and specifically affects the HTTP response handling mechanisms within the webserver, making it a classic example of a URL redirection vulnerability that could enable phishing attacks or credential theft. According to CWE standards, this maps to CWE-601 URL Redirection to Untrusted Site, which is classified as a high-risk vulnerability due to its potential for user deception and data exfiltration.
The operational impact of this vulnerability extends beyond simple web browsing concerns and represents a significant threat to industrial network security. Attackers can exploit this weakness to conduct sophisticated social engineering campaigns where authenticated users are unknowingly redirected to malicious sites that may attempt to harvest credentials, deploy malware, or gather intelligence about the industrial environment. The fact that exploitation requires user interaction through a legitimate authentication session makes this vulnerability particularly dangerous because it bypasses traditional network-level security controls and operates within the trusted user context. This could potentially enable attackers to escalate privileges or access sensitive operational data, especially in environments where HMI devices serve as critical interfaces for industrial processes. The vulnerability's impact aligns with ATT&CK techniques such as T1566 (Phishing) and T1071.004 (Application Layer Protocol: DNS) as attackers could leverage this to establish persistent access through user compromise.
Organizations should implement immediate mitigations including applying the vendor-provided security patches for all affected devices and versions, implementing network segmentation to limit access to these HMI devices, and establishing strict access controls for web-based interfaces. Additional protective measures include deploying web application firewalls to monitor and filter suspicious URL redirection attempts, implementing user awareness training to recognize potentially malicious links, and conducting regular security assessments of industrial control system web interfaces. The vulnerability demonstrates the importance of securing all network-facing components within industrial environments and highlights the need for comprehensive security postures that extend beyond traditional IT security measures to include operational technology considerations. Regular vulnerability assessments and security updates should be prioritized to prevent exploitation of similar weaknesses in industrial control system components.