CVE-2020-6090 in PFC 200
Summary
by MITRE
An exploitable code execution vulnerability exists in the Web-Based Management (WBM) functionality of WAGO PFC 200 03.03.10(15). A specially crafted series of HTTP requests can cause code execution resulting in remote code execution. An attacker can make an authenticated HTTP request to trigger this vulnerability.
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Analysis
by VulDB Data Team • 06/12/2020
The vulnerability identified as CVE-2020-6090 represents a critical code execution flaw within the Web-Based Management interface of WAGO PFC 200 series industrial control devices. This vulnerability specifically affects firmware version 03.03.10(15) and demonstrates how industrial control systems can be compromised through web-based attack vectors. The affected WAGO PFC 200 devices are widely deployed in industrial environments for process control and automation, making this vulnerability particularly concerning for operational technology infrastructure. The flaw exists within the device's web management functionality, which is typically used by administrators to configure and monitor industrial processes through standard web browsers. This creates a direct attack surface that can be exploited by malicious actors with network access to the device.
The technical implementation of this vulnerability stems from insufficient input validation within the web management interface's request processing mechanisms. When an authenticated user submits a specially crafted series of HTTP requests through the WBM interface, the system fails to properly sanitize or validate the incoming data before processing it. This lack of proper input validation creates a path for arbitrary code execution on the target device. The vulnerability requires authentication, meaning that an attacker must first obtain valid credentials to exploit the flaw, but once authenticated, the attacker can execute arbitrary commands with the privileges of the authenticated user. This type of vulnerability maps directly to CWE-77 and CWE-94, which describe improper input validation and code injection weaknesses respectively, and aligns with ATT&CK technique T1059.007 for command and script injection. The authentication requirement suggests that the vulnerability may be exploitable through credential theft or social engineering attacks that could compromise administrative accounts.
The operational impact of this vulnerability extends far beyond simple remote code execution, particularly in industrial control environments where these devices operate critical infrastructure. Successful exploitation could allow an attacker to modify device configurations, disrupt industrial processes, or gain persistent access to industrial networks. The implications are severe because WAGO PFC 200 devices are commonly used in manufacturing environments, power generation facilities, and other critical infrastructure sectors where process control and automation are essential. An attacker who gains remote code execution could potentially manipulate industrial processes, cause production disruptions, or create conditions that could lead to physical damage to equipment. The vulnerability's presence in the web management interface means that attackers could potentially exploit it through network-based attacks without requiring physical access to the device, making it particularly dangerous for industrial environments that may not have robust network segmentation. This aligns with ATT&CK tactic TA0008 (Lateral Movement) and TA0004 (Privilege Escalation) as attackers could use the compromised device as a foothold to move laterally within industrial networks.
Mitigation strategies for CVE-2020-6090 should focus on both immediate remediation and long-term security enhancements. The primary recommendation is to upgrade the affected WAGO PFC 200 devices to firmware versions that address this vulnerability, which would typically be provided by WAGO as part of their security patch management process. Organizations should also implement strict access controls for web management interfaces, including requiring multi-factor authentication for administrative accounts and limiting network access to these interfaces through firewalls and network segmentation. Network monitoring should be enhanced to detect unusual HTTP request patterns that might indicate exploitation attempts, and regular security audits should be conducted to identify and remediate similar vulnerabilities in industrial control systems. The vulnerability highlights the importance of secure coding practices in industrial environments and the need for regular security assessments of operational technology infrastructure. Organizations should also consider implementing network access control measures that limit which systems can communicate with industrial control devices, reducing the attack surface for web-based exploits. Additionally, security awareness training for industrial control system operators should include recognition of potential credential theft attacks that could lead to exploitation of authenticated vulnerabilities like CVE-2020-6090.