CVE-2012-4689 in Intelligent Platforms Proficy Hmi
Summary
by MITRE
Integer overflow in CimWebServer.exe in GE Intelligent Platforms Proficy HMI/SCADA - CIMPLICITY 4.01 through 8.0, and Proficy Process Systems with CIMPLICITY, allows remote attackers to cause a denial of service (daemon crash) via a malformed HTTP request.
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Analysis
by VulDB Data Team • 02/06/2018
The vulnerability identified as CVE-2012-4689 represents a critical integer overflow flaw within the CimWebServer.exe component of GE Intelligent Platforms Proficy HMI/SCADA systems running CIMPLICITY versions 4.01 through 8.0. This issue specifically affects industrial control systems that rely on web-based interfaces for monitoring and control operations, creating a significant security risk for critical infrastructure environments. The flaw exists in the web server implementation that processes HTTP requests, making it accessible to remote attackers who can exploit this vulnerability without requiring physical access or elevated privileges. The affected systems operate within industrial environments where continuous operation is paramount, making denial of service attacks particularly dangerous as they can disrupt critical manufacturing and process control operations.
The technical implementation of this vulnerability stems from improper input validation within the HTTP request processing logic of CimWebServer.exe. When the web server receives a malformed HTTP request containing specially crafted integer values, it fails to properly handle integer overflow conditions during request parsing or resource allocation operations. This occurs when the server attempts to convert or process request parameters that exceed the maximum representable value for the target integer data type, causing the application to behave unpredictably. The overflow condition typically manifests when the server allocates memory or processes counters based on malformed input values, leading to memory corruption or unexpected program execution paths. This type of vulnerability falls under CWE-190, which specifically addresses integer overflow and underflow conditions, and represents a classic example of improper integer handling in network services. The vulnerability is particularly concerning because it affects the core web server functionality that industrial operators use to access system information and control processes remotely.
The operational impact of this vulnerability extends far beyond simple service disruption, as it can severely compromise industrial control system availability and operational integrity. Remote attackers can exploit this weakness to crash the CimWebServer.exe daemon, effectively removing the web interface that operators rely on for monitoring and controlling industrial processes. This disruption can cascade into larger operational issues where system administrators lose visibility into critical processes, potentially leading to production halts, safety concerns, or compliance violations in regulated environments. The attack vector requires only network access to the affected system, making it particularly dangerous as it can be exploited from anywhere on the network, including from the internet if the system is improperly configured. The vulnerability affects systems that are often operational 24/7, meaning that even brief service interruptions can have significant financial and safety implications for industrial operations. According to ATT&CK framework, this vulnerability maps to T1499.004, which covers network denial of service attacks, and represents a critical weakness in industrial control system security posture.
Mitigation strategies for CVE-2012-4689 must address both immediate defensive measures and long-term architectural improvements. Organizations should implement network segmentation to isolate industrial control systems from general network access, reducing the attack surface available to potential attackers. Network access controls should be configured to limit HTTP access to trusted networks only, and additional monitoring should be deployed to detect malformed HTTP requests that could indicate exploitation attempts. GE Intelligent Platforms released patches and updates to address this vulnerability, and system administrators should ensure all affected systems are updated to the latest available versions. Implementing intrusion detection systems with signature-based detection for known attack patterns related to this vulnerability can provide early warning of exploitation attempts. Additionally, organizations should consider implementing web application firewalls specifically designed for industrial control systems to filter malicious requests before they reach the vulnerable web server component. Regular security assessments and vulnerability scanning of industrial control systems should include checks for this specific vulnerability and similar integer overflow conditions. The remediation process should also involve thorough testing of patches in controlled environments before deployment to production systems to ensure that updates do not introduce compatibility issues with existing industrial processes or applications.