CVE-2011-4056 in Tecnomatix FactoryLink
Summary
by MITRE
An unspecified ActiveX control in ActBar.ocx 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 create or overwrite arbitrary files via the save method.
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Analysis
by VulDB Data Team • 05/06/2017
The vulnerability identified as CVE-2011-4056 resides within the ActBar.ocx ActiveX control component of Siemens Tecnomatix FactoryLink software across multiple versions including 6.6.1, 7.5.217, and 8.0.2.54. This represents a critical security flaw that exposes industrial automation systems to potential remote exploitation. The ActiveX control, which is designed to provide user interface elements and functionality within web-based industrial applications, contains a dangerous method implementation that allows unauthorized file manipulation operations. The vulnerability specifically manifests through the save method of the ActBar.ocx control, which lacks proper input validation and access control mechanisms. This flaw enables remote attackers to execute arbitrary file creation or overwriting operations on systems where the vulnerable software is installed, potentially compromising the integrity of industrial control systems. The vulnerability falls under the category of insecure direct object reference as defined by CWE-22, where the control directly accepts user-provided file paths without proper validation or sanitization, creating an attack surface that can be exploited to manipulate critical system files.
The technical implementation of this vulnerability stems from the ActiveX control's failure to properly validate the file paths provided to its save method. When an attacker crafts a malicious web page or exploits a compromised web application that loads the vulnerable ActBar.ocx control, they can invoke the save method with arbitrary file paths. The control processes these paths without sufficient sanitization, allowing attackers to specify locations outside of intended directories, potentially overwriting system-critical files or creating malicious files with elevated privileges. This flaw represents a classic example of improper input validation and inadequate access controls, commonly classified under CWE-73 and CWE-20. The vulnerability is particularly concerning in industrial environments where FactoryLink software is used for managing manufacturing processes and control systems, as it could enable attackers to disrupt operations or gain deeper system access. The attack vector requires remote exploitation through web-based interfaces, making it accessible to attackers without physical access to the industrial control systems, aligning with ATT&CK technique T1190 for exploitation of web applications and T1059 for command and scripting interpreter usage.
The operational impact of CVE-2011-4056 extends significantly beyond simple file manipulation, potentially compromising the integrity and availability of industrial control systems. An attacker who successfully exploits this vulnerability could overwrite critical system files, install malicious software, or create backdoor access points within the industrial network infrastructure. The implications are severe in environments where FactoryLink is used for process control, as this could lead to production disruptions, safety hazards, or unauthorized access to sensitive operational data. The vulnerability affects multiple versions of Siemens Tecnomatix FactoryLink, indicating a widespread exposure across industrial installations that may not have been properly updated or patched. Organizations using this software in critical infrastructure environments face significant risk of operational compromise, as the vulnerability can be exploited through standard web browser interactions without requiring specialized tools or deep technical knowledge. The attack could potentially lead to lateral movement within industrial networks, as the compromised system might serve as a foothold for further exploitation of connected industrial control systems, making this vulnerability particularly dangerous in complex industrial environments where multiple interconnected systems exist.
Mitigation strategies for CVE-2011-4056 should focus on immediate remediation through official software updates from Siemens, as well as network-level protections to prevent exploitation. Organizations should disable ActiveX controls in web browsers where possible, particularly in industrial environments where such controls are not required for legitimate operations. Network segmentation and access controls should be implemented to limit exposure of vulnerable systems to external networks, while monitoring for suspicious file creation or modification activities. Security administrators should conduct comprehensive vulnerability assessments to identify all instances of the affected software across their industrial control networks, ensuring that patches are applied consistently across all affected systems. The implementation of web application firewalls and content filtering solutions can provide additional protection layers against exploitation attempts, while regular security audits should verify that no unauthorized modifications have occurred to system files. Organizations should also consider implementing principle of least privilege access controls and regular system integrity checks to detect potential compromise of industrial control systems. The vulnerability demonstrates the importance of maintaining updated industrial control system software and implementing robust security practices specifically tailored for operational technology environments, as the traditional cybersecurity approaches may not be sufficient to protect against exploitation of legacy industrial software components.