CVE-2017-6867 in SIMATIC WinCC
Summary
by MITRE
A vulnerability was discovered in Siemens SIMATIC WinCC (V7.3 before Upd 11 and V7.4 before SP1), SIMATIC WinCC Runtime Professional (V13 before SP2 and V14 before SP1), SIMATIC WinCC (TIA Portal) Professional (V13 before SP2 and V14 before SP1) that could allow an authenticated, remote attacker who is member of the "administrators" group to crash services by sending specially crafted messages to the DCOM interface.
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Analysis
by VulDB Data Team • 12/06/2022
This vulnerability exists within Siemens industrial automation software products including SIMATIC WinCC and related runtime environments. The flaw resides in the Distributed Component Object Model DCOM interface implementation which handles remote communication between system components. An authenticated attacker possessing administrator privileges can exploit this weakness by transmitting specifically crafted messages that trigger service crashes. The vulnerability affects multiple versions of Siemens WinCC products including V7.3 before Upd 11, V7.4 before SP1, and various runtime versions through their respective service packs. This represents a critical security issue as it allows for remote service disruption through legitimate administrative access points.
The technical implementation of the vulnerability stems from improper input validation within the DCOM interface layer. When the system processes maliciously constructed messages, it fails to properly sanitize or validate the incoming data structures, leading to buffer overflows or memory corruption conditions. This type of flaw aligns with CWE-121, which describes stack-based buffer overflow conditions, and CWE-125, which addresses out-of-bounds read vulnerabilities. The DCOM interface serves as a communication channel for remote administration and monitoring functions, making it a prime target for exploitation. Attackers can leverage this weakness to cause denial of service conditions that disrupt critical industrial control processes.
From an operational perspective, this vulnerability poses significant risks to industrial control systems where WinCC software serves as the primary human-machine interface. The ability to remotely crash services can lead to production downtime, operational disruptions, and potential safety hazards in critical infrastructure environments. The requirement for administrator-level access limits the attack surface somewhat but does not eliminate the threat, as successful exploitation can occur through credential compromise or lateral movement within networks. This vulnerability is particularly concerning in environments where operational technology systems are directly connected to corporate networks, as it provides a pathway for attackers to escalate privileges and cause cascading failures. The impact extends beyond simple service disruption to potentially compromising the integrity of industrial processes and control systems.
Organizations should implement immediate mitigations including applying the latest security patches from Siemens, which address the DCOM interface validation issues. Network segmentation should be enforced to limit access to WinCC systems, with strict firewall rules controlling DCOM communication ports. The principle of least privilege must be applied to administrator accounts, with multi-factor authentication implemented where possible. Regular security assessments should include vulnerability scanning of industrial control systems to identify similar weaknesses. Additionally, monitoring systems should be configured to detect unusual DCOM activity patterns that might indicate exploitation attempts. The vulnerability demonstrates the importance of securing industrial communication interfaces and highlights the need for robust patch management processes in operational technology environments. According to ATT&CK framework, this vulnerability maps to T1072 for software deployment and T1499 for endpoint disruption, emphasizing both the attack vectors and potential impact on system availability.