CVE-2019-5157 in PFC200
Summary
by MITRE
An exploitable command injection vulnerability exists in the Cloud Connectivity functionality of WAGO PFC200 Firmware versions 03.02.02(14), 03.01.07(13), and 03.00.39(12). An attacker can inject OS commands into the TimeoutUnconfirmed parameter value contained in the Firmware Update command.
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Analysis
by VulDB Data Team • 04/13/2024
The vulnerability identified as CVE-2019-5157 represents a critical command injection flaw within the WAGO PFC200 industrial automation device firmware, specifically affecting versions 03.02.02(14), 03.01.07(13), and 03.00.39(12). This weakness resides in the Cloud Connectivity functionality where the device processes firmware update commands, creating a pathway for malicious actors to execute arbitrary operating system commands on the affected system. The vulnerability manifests when an attacker manipulates the TimeoutUnconfirmed parameter value within the Firmware Update command, allowing unauthorized command execution with the privileges of the affected service account.
This command injection vulnerability directly maps to CWE-77, which categorizes improper neutralization of special elements used in OS commands. The flaw stems from inadequate input validation and sanitization within the firmware's parameter handling mechanism, where user-supplied data flows directly into system command execution contexts without proper sanitization. The affected WAGO PFC200 devices operate in industrial control environments where command injection can have severe operational technology implications, potentially allowing attackers to gain unauthorized access to critical infrastructure control systems. The vulnerability's exploitation requires minimal privileges since it targets the firmware update functionality, which typically operates with elevated permissions necessary for system modifications.
The operational impact of this vulnerability extends beyond simple command execution, as it can enable attackers to establish persistent access, escalate privileges, and potentially disrupt industrial processes. In industrial control systems, such vulnerabilities can lead to production halts, safety system compromise, and unauthorized data manipulation. The attack surface is particularly concerning given that these devices often operate in isolated networks but may have cloud connectivity features that expose them to remote exploitation. The vulnerability's presence in multiple firmware versions indicates a widespread issue affecting various deployments of WAGO PFC200 devices across industrial environments, making it a significant concern for operational technology security.
Mitigation strategies for CVE-2019-5157 should focus on immediate firmware updates from WAGO to address the command injection flaw, while implementing network segmentation to limit access to affected devices. Organizations should also consider disabling cloud connectivity features when not required and implementing strict access controls for firmware update operations. The vulnerability aligns with ATT&CK technique T1059.001 for command and scripting interpreter, where adversaries execute commands through legitimate system interfaces. Security monitoring should include detection of unusual command execution patterns and parameter manipulation attempts within firmware update processes. Network-based intrusion detection systems should be configured to identify suspicious TimeoutUnconfirmed parameter values that could indicate exploitation attempts. Regular security assessments of industrial control system firmware should be conducted to identify similar vulnerabilities in other operational technology devices.