CVE-2018-7502 in TwinCAT
Summary
by MITRE
Kernal drivers in Beckhoff TwinCAT 3.1 Build 4022.4, TwinCAT 2.11 R3 2259, and TwinCAT 3.1 lack proper validation of user-supplied pointer values. An attacker who is able to execute code on the target may be able to exploit this vulnerability to obtain SYSTEM privileges.
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Analysis
by VulDB Data Team • 01/16/2020
The vulnerability identified as CVE-2018-7502 represents a critical kernel-level flaw affecting Beckhoff TwinCAT automation software versions 3.1 Build 4022.4, 2.11 R3 2259, and related iterations. This issue manifests in the kernel drivers where insufficient validation mechanisms exist for user-provided pointer values, creating a pathway for privilege escalation attacks. The vulnerability specifically impacts industrial automation systems that rely on TwinCAT for control and monitoring operations, making it particularly concerning for operational technology environments where system integrity is paramount.
The technical root cause of this vulnerability lies in the improper handling of pointer parameters within the kernel driver components of TwinCAT software. When user applications or malicious code interact with these drivers, the system fails to adequately validate the pointer values supplied by untrusted sources. This validation gap allows an attacker who has already achieved code execution on the target system to manipulate kernel memory structures through crafted pointer inputs. The flaw essentially creates a condition where user-supplied data can be directly dereferenced without proper bounds checking or access control verification, enabling malicious actors to bypass normal security boundaries.
The operational impact of CVE-2018-7502 extends beyond typical privilege escalation scenarios due to the industrial control environment in which TwinCAT operates. Successful exploitation can grant attackers SYSTEM privileges, effectively providing complete control over the target machine and its connected industrial processes. This level of access could enable attackers to manipulate production processes, disrupt operations, or potentially cause physical damage to industrial equipment. The vulnerability is particularly dangerous in environments where TwinCAT controls critical infrastructure such as manufacturing lines, power generation systems, or process control facilities. The attack vector requires initial code execution on the target system, which may occur through various means including phishing attacks, unpatched software vulnerabilities, or social engineering tactics.
Organizations utilizing affected TwinCAT versions should prioritize immediate remediation through official vendor patches and updates. The vulnerability aligns with CWE-125, which describes out-of-bounds read conditions in software systems, and potentially relates to CWE-787, representing out-of-bounds write vulnerabilities that could be exploited through similar pointer manipulation techniques. From an adversarial perspective, this vulnerability would be categorized under ATT&CK technique T1068, which covers local privilege escalation through kernel exploits, and T1059, covering command and scripting interpreters for execution. System administrators should implement network segmentation to limit access to systems running TwinCAT, disable unnecessary services, and monitor for anomalous behavior that might indicate exploitation attempts. Additionally, regular security assessments and vulnerability scanning should be conducted to identify and remediate similar issues in industrial control systems and other embedded automation platforms.