CVE-2017-2684 in SIMATIC Logon
Summary
by MITRE
Siemens SIMATIC Logon prior to V1.5 SP3 Update 2 could allow an attacker with knowledge of a valid user name, and physical or network access to the affected system, to bypass the application-level authentication.
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Analysis
by VulDB Data Team • 09/02/2020
The vulnerability identified as CVE-2017-2684 affects Siemens SIMATIC Logon software versions prior to V1.5 SP3 Update 2, representing a critical authentication bypass flaw that undermines the security posture of industrial control systems. This vulnerability resides within the application-level authentication mechanism of the SIMATIC Logon component, which serves as a centralized authentication solution for Siemens industrial automation and control systems. The flaw specifically enables attackers to circumvent the standard authentication process without requiring valid credentials, provided they possess knowledge of a legitimate username and have either physical access to the target system or network access to the affected environment.
The technical implementation of this vulnerability stems from insufficient validation of authentication tokens and session management within the SIMATIC Logon application. Attackers can exploit this weakness by leveraging the known username to manipulate the authentication flow, effectively allowing unauthorized access to industrial control systems without proper authorization. This flaw operates at the application layer and can be particularly dangerous in industrial environments where operational technology (OT) systems are interconnected with corporate networks, creating potential attack vectors that bridge the gap between IT and OT security domains.
The operational impact of CVE-2017-2684 extends beyond simple unauthorized access, as it can lead to complete system compromise within industrial environments. Attackers who successfully exploit this vulnerability can gain access to critical industrial processes, potentially leading to disruption of operations, data manipulation, or even physical safety risks in manufacturing and process control environments. The vulnerability's exploitation requires minimal privileges and can be executed remotely, making it particularly concerning for organizations with distributed industrial control systems. This authentication bypass represents a significant risk to the integrity and availability of industrial processes, as it allows attackers to assume legitimate user roles without proper verification.
Organizations should implement immediate mitigations including upgrading to SIMATIC Logon V1.5 SP3 Update 2 or later versions, which contain the necessary patches to address the authentication bypass vulnerability. Network segmentation and access controls should be strengthened to limit physical and network access to industrial systems, while monitoring solutions should be deployed to detect anomalous authentication patterns. The vulnerability aligns with CWE-287, which addresses improper authentication issues in software applications, and represents a significant concern under the ATT&CK framework's privilege escalation techniques. Security teams should also conduct comprehensive assessments of their industrial control system environments to identify potential exposure to similar authentication bypass vulnerabilities and establish robust monitoring procedures for detecting unauthorized access attempts.