CVE-2011-5086 in Unitronics UniOPC
Summary
by MITRE
https50.ocx in IP*Works! SSL in the server in Unitronics UniOPC before 2.0.0 does not properly implement an unspecified function, which allows remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code via a crafted web site.
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Analysis
by VulDB Data Team • 03/27/2019
The vulnerability identified as CVE-2011-5086 affects the https50.ocx component within IP*Works! SSL server implementation in Unitronics UniOPC versions prior to 2.0.0. This flaw resides in the improper implementation of an unspecified function within the ActiveX control that handles secure hypertext transfer protocol communications. The vulnerability represents a critical security weakness that could be exploited by remote attackers to compromise system integrity and availability. The affected component is part of a broader suite of industrial automation and communication tools that facilitate secure data exchange between OPC (OLE for Process Control) servers and clients in industrial environments.
The technical implementation flaw manifests through the inadequate handling of function calls within the https50.ocx ActiveX control, creating potential buffer overflows or memory corruption conditions that can be triggered by maliciously crafted web content. This unspecified function implementation fails to properly validate input parameters or enforce proper boundary checks, allowing attackers to manipulate memory structures through carefully constructed requests. The vulnerability falls under the category of improper input validation and memory safety issues, which are commonly classified as CWE-121 for buffer overflow conditions or CWE-787 for out-of-bounds write operations. The attack vector involves remote exploitation through web-based interfaces that utilize the vulnerable ActiveX control, making it particularly dangerous in environments where industrial control systems are accessible via web protocols.
The operational impact of this vulnerability extends beyond simple denial of service conditions to potentially enable arbitrary code execution on affected systems. When exploited successfully, attackers can cause application crashes that result in service interruption, while more sophisticated attacks may allow for complete system compromise and privilege escalation. The vulnerability affects industrial environments that rely on Unitronics UniOPC for secure communications, potentially impacting critical infrastructure operations where continuous availability is essential. The implications are particularly severe given that many industrial control systems operate in environments where traditional security measures may be limited, and system downtime can result in significant operational disruptions and safety concerns.
Mitigation strategies for this vulnerability require immediate patching of affected systems to upgrade to Unitronics UniOPC version 2.0.0 or later, which contains the necessary fixes for the https50.ocx function implementation. Organizations should also implement network segmentation to limit access to systems running vulnerable components, particularly those exposed to external networks. The remediation process should include comprehensive vulnerability scanning to identify all instances of the affected ActiveX control and proper access controls to prevent unauthorized execution of malicious web content. Additionally, implementing application whitelisting policies and disabling unnecessary ActiveX controls in web browsers can significantly reduce the attack surface. This vulnerability demonstrates the importance of proper software security practices in industrial control systems and aligns with ATT&CK tactics including T1203 for Exploitation for Execution and T1499 for Endpoint Termination, highlighting the need for robust security controls in operational technology environments.