CVE-2018-5459 in PFC200 Series 3S CoDeSys Runtime
Summary
by MITRE
An Improper Authentication issue was discovered in WAGO PFC200 Series 3S CoDeSys Runtime versions 2.3.X and 2.4.X. An attacker can execute different unauthenticated remote operations because of the CoDeSys Runtime application, which is available via network by default on Port 2455. An attacker could execute some unauthenticated commands such as reading, writing, or deleting arbitrary files, or manipulate the PLC application during runtime by sending specially-crafted TCP packets to Port 2455.
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Analysis
by VulDB Data Team • 01/04/2020
The vulnerability identified as CVE-2018-5459 represents a critical improper authentication flaw within WAGO PFC200 Series 3S CoDeSys Runtime systems. This issue affects specific versions 2.3.X and 2.4.X of the CoDeSys Runtime application, creating a significant security risk for industrial control systems. The vulnerability stems from the default network exposure of the CoDeSys Runtime application on TCP port 2455, which lacks proper authentication mechanisms to verify the identity of connecting entities. This misconfiguration allows unauthorized access to critical system functions that should only be available to authenticated administrators or authorized personnel. The flaw directly violates fundamental security principles of access control and authentication, creating a pathway for malicious actors to compromise industrial automation environments.
The technical implementation of this vulnerability exploits the absence of authentication checks within the CoDeSys Runtime application's network interface. When the application listens on port 2455 by default, it accepts incoming TCP connections without requiring any form of credential validation or authorization verification. Attackers can craft specially designed TCP packets to communicate with the vulnerable application and execute a range of malicious operations including reading arbitrary files from the system, writing new files or modifying existing ones, deleting critical system components, and manipulating PLC application behavior during runtime execution. This functionality enables attackers to perform operations such as code injection, data manipulation, and system disruption without requiring legitimate credentials or access rights. The vulnerability operates at the application layer of the network stack and leverages the inherent trust model of the default configuration to gain unauthorized access to industrial control functions.
The operational impact of this vulnerability extends far beyond simple unauthorized access, as it provides attackers with complete control over industrial processes and automation systems. The ability to read, write, or delete arbitrary files on the PLC system creates opportunities for data theft, system corruption, or complete system compromise. Manipulation of PLC application behavior during runtime can lead to production disruptions, safety hazards, or even physical damage to industrial equipment. This vulnerability particularly affects critical infrastructure environments where industrial control systems manage manufacturing processes, power generation, or other essential services. The remote nature of the attack means that adversaries can exploit this vulnerability from anywhere on the network without requiring physical access to the industrial control system, making it especially dangerous for environments with limited physical security controls. The vulnerability's presence in widely deployed industrial control systems creates a significant risk for organizations operating in sectors such as manufacturing, energy, and process control.
Organizations affected by this vulnerability should implement immediate mitigations to protect their industrial control systems. The primary recommended action involves disabling the CoDeSys Runtime application's network interface or restricting access to port 2455 through network firewalls and access control lists. Network segmentation should be implemented to isolate industrial control systems from general enterprise networks, limiting potential attack vectors. Additionally, organizations should consider disabling unnecessary services and applications that are not required for operational functions. Regular security assessments and vulnerability scanning should be conducted to identify similar misconfigurations within industrial control system environments. The vulnerability aligns with CWE-287, which addresses improper authentication issues in software systems, and represents a clear violation of the principle of least privilege. From an ATT&CK framework perspective, this vulnerability maps to techniques involving remote service exploitation and privilege escalation, with potential for lateral movement within industrial networks. Organizations should also consider implementing network monitoring and anomaly detection systems to identify suspicious network traffic patterns that may indicate exploitation attempts against industrial control systems.