CVE-2016-5787 in Digital Proficy HMI
Summary
by MITRE
General Electric (GE) Digital Proficy HMI/SCADA - CIMPLICITY before 8.2 SIM 27 mishandles service DACLs, which allows local users to modify a service configuration via unspecified vectors.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 02/27/2019
The vulnerability identified as CVE-2016-5787 affects GE Digital Proficy HMI/SCADA - CIMPLICITY software versions prior to 8.2 SIM 27, representing a critical access control flaw that undermines the security posture of industrial control systems. This issue specifically targets the handling of Discretionary Access Control Lists within the service configuration management framework, creating a pathway for local attackers to manipulate system configurations without proper authorization. The vulnerability falls under the category of insufficient access control as defined by CWE-284, where inadequate permission checks allow unauthorized modifications to system services.
The technical exploitation of this vulnerability occurs through unspecified vectors that leverage the improper handling of DACLs in the CIMPLICITY service management components. Local users who can access the system with standard privileges can potentially modify service configurations, which may lead to privilege escalation or service disruption. This flaw represents a significant concern for industrial environments where CIMPLICITY is deployed for supervisory control and data acquisition purposes, as it directly impacts the integrity and availability of critical infrastructure monitoring systems. The vulnerability demonstrates a failure in the principle of least privilege and proper service configuration management.
From an operational impact perspective, this vulnerability poses substantial risks to industrial control environments that rely on CIMPLICITY for process monitoring and control. Attackers could potentially modify service configurations to disable critical monitoring functions, redirect data flows, or establish persistent access mechanisms within the industrial network. The local nature of the attack vector means that an attacker would need initial access to the system, but once achieved, could significantly compromise the integrity of the SCADA environment. This vulnerability aligns with ATT&CK technique T1068 which involves local privilege escalation and system modification, potentially enabling further attacks within the industrial network.
The mitigation strategy for CVE-2016-5787 requires immediate deployment of the vendor-provided patch for CIMPLICITY version 8.2 SIM 27 or later, which addresses the DACL handling issue in service configuration management. Organizations should also implement comprehensive access control policies that limit local user privileges and monitor service configuration changes through audit logging mechanisms. Network segmentation and the principle of least privilege should be enforced to minimize the potential impact of local privilege escalation. Additionally, regular security assessments of industrial control systems should include evaluation of service configuration management processes and access control implementations, as this vulnerability represents a common weakness in industrial automation environments where operational requirements may conflict with security best practices. The remediation process should also involve comprehensive testing of updated configurations to ensure that service modifications do not disrupt critical industrial processes while maintaining security controls.