CVE-2015-1356 in SIMATIC Step 7
Summary
by MITRE
Siemens SIMATIC STEP 7 (TIA Portal) before 13 SP1 determines a user s privileges on the basis of project-file fields that lack integrity protection, which allows remote attackers to establish arbitrary authorization data via a modified file.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 04/16/2022
The vulnerability identified as CVE-2015-1356 affects Siemens SIMATIC STEP 7 (TIA Portal) versions prior to 13 SP1, representing a critical authorization bypass flaw that undermines the security model of industrial automation software. This vulnerability resides within the project file handling mechanism of the TIA Portal environment, which is widely used for programming and configuring industrial control systems. The flaw stems from insufficient integrity protection mechanisms applied to project file metadata that contains user privilege information, creating an exploitable condition that allows malicious actors to manipulate authorization data without proper authentication.
The technical implementation of this vulnerability exploits the absence of cryptographic integrity checks or validation mechanisms on project file fields that store user access rights and privileges. When the TIA Portal application loads project files, it relies on these unverified fields to determine user permissions, effectively trusting the integrity of data that can be modified by attackers. This design flaw aligns with CWE-353, which addresses the lack of integrity protection in security-critical data, and represents a classic case of insufficient validation of security-relevant data. The vulnerability enables remote attackers to modify project files containing user privilege information, subsequently allowing them to assume arbitrary authorization levels within the industrial control environment.
The operational impact of CVE-2015-1356 extends beyond simple privilege escalation, as it can lead to complete compromise of industrial control systems. An attacker who successfully exploits this vulnerability can gain unauthorized access to critical system functions, modify program logic, alter operational parameters, or even disable safety mechanisms within industrial processes. This risk is particularly severe in environments where TIA Portal is used for configuring PLCs, HMIs, and other critical infrastructure components, as the compromised authorization data can be leveraged to execute malicious code or manipulate industrial processes. The vulnerability's remote exploitability means that attackers do not require physical access to the system, making it particularly dangerous in networked industrial environments.
Mitigation strategies for this vulnerability must address both the immediate security gap and broader industrial security practices. Organizations should immediately update to TIA Portal version 13 SP1 or later, which includes proper integrity protection mechanisms for project file metadata. Additionally, implementing network segmentation, access controls, and regular security audits of industrial control system environments can help reduce the attack surface. The vulnerability demonstrates the importance of applying the principle of least privilege and integrity protection in industrial control systems, aligning with ATT&CK technique T1548.001 for privilege escalation and T1071.004 for application layer protocols. Security professionals should also consider implementing file integrity monitoring solutions and ensuring that project files are properly secured through cryptographic means to prevent unauthorized modifications that could lead to system compromise.