CVE-2025-4384 in PcVue
Summary
by MITRE • 05/06/2025
The MQTT add-on of PcVue fails to verify that a remote device’s certificate has not already expired or has not yet become valid. This allows malicious devices to present certificates that are not rejected properly.
The use of a client certificate reduces the risk for random devices to take advantage of this flaw.
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Analysis
by VulDB Data Team • 05/06/2025
The vulnerability identified as CVE-2025-4384 affects the MQTT add-on component within PcVue industrial automation software, presenting a critical security weakness in certificate validation processes. This flaw resides in the certificate verification mechanism that governs secure communications between devices and the PcVue system. The vulnerability stems from the absence of proper certificate validity checks that should ensure certificates are neither expired nor prematurely valid. According to CWE-295, this represents a failure in certificate validation controls that can lead to unauthorized access and potential system compromise. The issue specifically impacts the TLS/SSL certificate validation process where the system should verify certificate expiration dates and validity periods before establishing secure connections.
The technical implementation flaw manifests when the MQTT add-on processes incoming client certificates without performing essential time-based validation checks. This allows malicious actors to present certificates that have expired or are not yet valid, yet the system accepts them as legitimate. The vulnerability operates at the transport layer security validation level, where proper certificate chain validation should include checking not only the certificate authority but also temporal validity parameters. This weakness creates an attack surface where compromised or forged certificates can bypass authentication mechanisms, potentially enabling man-in-the-middle attacks or unauthorized device access to the industrial control system. The vulnerability aligns with ATT&CK technique T1566 which involves phishing attacks through social engineering, as attackers could exploit this weakness to present fraudulent certificates to gain system access.
The operational impact of CVE-2025-4384 extends beyond simple authentication bypass, potentially allowing attackers to disrupt industrial processes or gain unauthorized access to critical control systems. In industrial environments where PcVue manages process control and monitoring, this vulnerability could enable attackers to manipulate data flows, introduce false readings, or even take control of connected devices. The risk is particularly concerning in environments with limited network segmentation where a compromised device could potentially move laterally within the industrial network. The mitigation effectiveness of client certificates, while providing some protection, does not fully address this vulnerability since the system still fails to validate certificate temporal parameters regardless of certificate type. Organizations using PcVue in industrial control systems should consider this vulnerability as potentially exploitable in targeted attacks against critical infrastructure.
The security implications of this vulnerability underscore the importance of proper certificate management and validation procedures in industrial environments. The lack of certificate expiration checking creates a persistent risk where attackers can maintain access through expired certificates or use certificates that have not yet become valid. This vulnerability highlights the need for comprehensive certificate validation that includes time-based checks as part of the security architecture. Organizations should implement additional monitoring and validation controls beyond the default certificate verification process to detect and prevent exploitation attempts. The vulnerability demonstrates how seemingly minor validation gaps can create significant security risks in industrial control systems where security is paramount. Proper implementation of certificate validation should include checking certificate validity periods, revocation status, and proper chain of trust verification to prevent this type of exploitation.