CVE-2016-4516 in PCM600
Summary
by MITRE
ABB PCM600 before 2.7 improperly stores the main application password after a password change, which allows local users to obtain sensitive information via unspecified vectors.
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Analysis
by VulDB Data Team • 01/14/2019
The CVE-2016-4516 vulnerability affects ABB PCM600 devices running firmware versions prior to 2.7, representing a critical security flaw in industrial control systems that undermines the integrity of authentication mechanisms. This vulnerability specifically targets the password management functionality within the device's main application, creating a persistent security weakness that can be exploited by local attackers to gain unauthorized access to sensitive system information. The improper handling of password storage after a change operation creates a scenario where authentication credentials remain accessible in cleartext or through alternative data structures, fundamentally compromising the security posture of the industrial control environment.
The technical flaw manifests in the device's failure to properly overwrite or securely dispose of the previous password value when a password change occurs. This insecure implementation allows local users to potentially access the old password through various means including memory inspection, file system analysis, or direct application interfaces. The vulnerability's unspecified vectors suggest multiple attack paths may be available, including but not limited to memory dumps, process inspection, or exploitation of the device's internal data structures. This weakness aligns with CWE-256, which addresses the improper handling of sensitive information, and represents a classic case of credential exposure through inadequate data sanitization practices. The vulnerability specifically targets the authentication and authorization mechanisms that are fundamental to industrial control systems, where unauthorized access can lead to significant operational disruptions and safety risks.
The operational impact of CVE-2016-4516 extends beyond simple credential theft, as it can enable attackers to escalate privileges and gain deeper access to industrial control systems. Local users who can exploit this vulnerability can potentially compromise the entire control environment, affecting critical infrastructure operations and industrial processes that rely on ABB PCM600 devices for monitoring and control functions. The attack surface is particularly concerning in industrial environments where physical access may be limited but still possible, making local privilege escalation a significant threat vector. This vulnerability can be exploited to maintain persistent access to the system, potentially allowing attackers to modify operational parameters, disrupt processes, or gather intelligence for more sophisticated attacks. The implications align with ATT&CK technique T1078 which covers valid accounts and privilege escalation through legitimate credentials.
Mitigation strategies for CVE-2016-4516 should prioritize immediate firmware updates to version 2.7 or later, which contain the necessary patches to properly handle password storage and removal. Organizations should implement comprehensive security monitoring to detect any unauthorized access attempts or suspicious activities that may indicate exploitation of this vulnerability. Additional protective measures include enforcing strict access controls, implementing network segmentation to limit local access points, and conducting regular security assessments of industrial control systems. System administrators should also consider implementing memory protection mechanisms and regular credential rotation policies to minimize the impact of such vulnerabilities. The vulnerability demonstrates the importance of proper secure coding practices and the necessity of thorough security testing in industrial control systems, where the consequences of credential exposure can be severe and far-reaching.