CVE-2023-37857 in WP 6xxx
Summary
by MITRE • 08/09/2023
In PHOENIX CONTACTs WP 6xxx series web panels in versions prior to 4.0.10 an authenticated, remote attacker with admin privileges is able to read hardcoded cryptographic keys allowing the attacker to create valid session cookies. This issue cannot be exploited to bypass the web service authentication of the affected device(s).
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Analysis
by VulDB Data Team • 09/02/2023
The vulnerability identified as CVE-2023-37857 affects PHOENIX CONTACT's WP 6xxx series web panels running firmware versions prior to 4.0.10. This represents a critical security flaw that exposes hardcoded cryptographic keys within the device's web interface implementation. The vulnerability specifically targets the session management mechanism of these industrial control devices, which are commonly deployed in industrial environments for human-machine interface (HMI) applications. These web panels serve as critical interfaces for operators to interact with industrial control systems, making their security paramount to overall industrial cybersecurity posture.
The technical flaw manifests through the improper handling of cryptographic keys within the authentication system of these devices. When an authenticated attacker with administrative privileges accesses the web panel, they can exploit a code path that reveals hardcoded cryptographic keys used for session cookie generation. This represents a violation of secure coding practices and directly relates to CWE-327, which addresses the use of weak cryptographic algorithms and improper key management. The hardcoded keys are typically embedded within the device firmware or configuration files, making them accessible to any user with administrative access through legitimate administrative interfaces. This flaw essentially undermines the session management security model by providing attackers with the means to forge valid session tokens that can impersonate legitimate administrative users.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it enables attackers to maintain persistent access to industrial control systems without triggering authentication mechanisms. While the vulnerability requires an existing administrative account to exploit, it significantly weakens the security boundary by allowing attackers to create session cookies that bypass normal authentication checks. This capability enables attackers to perform administrative functions, modify system configurations, access sensitive operational data, and potentially disrupt industrial processes. The vulnerability aligns with ATT&CK technique T1566 which covers credential harvesting through various means, and T1078 which addresses valid accounts usage for persistence. Industrial environments are particularly vulnerable to such attacks as they often have limited monitoring and detection capabilities for unusual administrative activities.
Mitigation strategies for CVE-2023-37857 require immediate firmware updates to version 4.0.10 or later, which addresses the hardcoded key exposure issue. Organizations should also implement additional security controls including network segmentation to isolate these devices from general corporate networks, implementing strict access controls with multi-factor authentication, and monitoring for suspicious session activity. The vulnerability highlights the importance of secure key management practices and proper implementation of cryptographic functions in embedded industrial systems. Security teams should conduct comprehensive vulnerability assessments of all PHOENIX CONTACT devices in their environment and consider implementing network access controls to limit administrative access to only necessary personnel. Regular security audits of industrial control systems should include checks for hardcoded credentials and cryptographic key exposure, as these issues represent common attack vectors in industrial environments.