CVE-2011-4055 in Tecnomatix FactoryLink
Summary
by MITRE
Buffer overflow in the WebClient ActiveX control in Siemens Tecnomatix FactoryLink 6.6.1 (aka 6.6 SP1), 7.5.217 (aka 7.5 SP2), and 8.0.2.54 allows remote attackers to execute arbitrary code via a long string in a parameter associated with the location URL.
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Analysis
by VulDB Data Team • 05/03/2017
The vulnerability identified as CVE-2011-4055 represents a critical buffer overflow flaw within the WebClient ActiveX control component of Siemens Tecnomatix FactoryLink software versions 6.6.1, 7.5.217, and 8.0.2.54. This security weakness resides in the handling of location URL parameters within the ActiveX control implementation, creating a pathway for remote code execution attacks. The vulnerability affects industrial automation and control systems where Siemens FactoryLink is deployed, potentially compromising critical infrastructure environments. The buffer overflow occurs when the WebClient ActiveX control processes a malformed parameter containing an excessively long string, exceeding the allocated buffer space and allowing attackers to overwrite adjacent memory locations.
The technical implementation of this vulnerability stems from inadequate input validation within the ActiveX control's parameter processing logic. When the control receives a location URL parameter containing a string longer than the predefined buffer capacity, the system fails to properly bounds-check the input data before copying it into memory. This classic buffer overflow condition enables attackers to inject malicious code into the execution flow by overwriting return addresses and function pointers in the program's memory space. The flaw is particularly dangerous because it operates through the ActiveX control interface, which is commonly enabled in web browsers and web-based applications, making exploitation possible through standard web browsing activities. The vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and represents a prime example of how legacy industrial software components can contain fundamental memory safety issues.
The operational impact of this vulnerability extends beyond typical remote code execution scenarios due to the industrial control systems environment where Siemens FactoryLink operates. Attackers who successfully exploit this vulnerability can gain complete control over the affected system, potentially leading to unauthorized access to industrial processes, data manipulation, or disruption of critical manufacturing operations. The implications are particularly severe in environments where FactoryLink is used for SCADA (Supervisory Control and Data Acquisition) systems, as these platforms often control physical processes and equipment. The vulnerability can be exploited remotely without requiring authentication, making it especially dangerous for systems connected to the internet or exposed to untrusted network zones. This aligns with ATT&CK technique T1203, which covers exploitation of remote services, and demonstrates how industrial control system vulnerabilities can be leveraged for broader operational disruption.
Mitigation strategies for CVE-2011-4055 require a multi-layered approach addressing both immediate remediation and long-term security enhancements. Organizations should prioritize applying the vendor-provided patches and updates for Siemens Tecnomatix FactoryLink versions affected by this vulnerability, as these releases typically contain memory safety improvements and input validation fixes. Network segmentation and access controls should be implemented to limit exposure of affected systems to untrusted networks, particularly by restricting direct internet access to systems running the vulnerable ActiveX controls. Browser security configurations should be adjusted to disable ActiveX controls or restrict their execution to trusted sites only, reducing the attack surface for web-based exploitation attempts. Additionally, implementing network monitoring and intrusion detection systems can help identify suspicious network traffic patterns associated with exploitation attempts, while regular security assessments of industrial control systems can help identify similar vulnerabilities in other legacy components. The vulnerability underscores the importance of maintaining up-to-date industrial software and implementing robust security practices in critical infrastructure environments, as these systems often remain operational for extended periods without regular security updates.