CVE-2011-4526 in WebAccess
Summary
by MITRE
Buffer overflow in an ActiveX control in Advantech/BroadWin WebAccess before 7.0 might allow remote attackers to execute arbitrary code via a long string value in unspecified parameters.
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Analysis
by VulDB Data Team • 04/10/2017
The vulnerability identified as CVE-2011-4526 represents a critical buffer overflow flaw within the ActiveX control component of Advantech/BroadWin WebAccess software versions prior to 7.0. This issue resides in the handling of user-supplied input within an ActiveX control that is typically deployed in industrial automation and monitoring environments. The vulnerability specifically manifests when the ActiveX control processes unspecified parameters containing excessively long string values, creating a condition where memory boundaries are exceeded and potentially allowing malicious code execution.
The technical nature of this flaw falls under the CWE-121 buffer overflow category, which occurs when data is written beyond the allocated buffer space in memory. In this case, the ActiveX control lacks proper input validation and bounds checking mechanisms when processing parameter values, particularly string inputs that exceed the expected buffer size. The vulnerability is classified as a remote code execution flaw because it can be exploited over a network without requiring local system access, making it particularly dangerous in industrial control systems where network connectivity is common. The buffer overflow occurs in the context of the ActiveX control's parameter handling routines, where insufficient bounds checking allows attackers to overwrite adjacent memory locations with malicious payloads.
The operational impact of this vulnerability is severe within industrial environments where Advantech/BroadWin WebAccess is deployed for SCADA (Supervisory Control and Data Acquisition) systems and process control applications. Attackers who successfully exploit this vulnerability can gain complete control over systems running vulnerable versions of the software, potentially leading to unauthorized access to critical infrastructure operations, data manipulation, or system disruption. The remote exploitation capability means that attackers do not need physical access to the target systems, and can potentially compromise multiple devices from a single attack vector. This vulnerability directly impacts the integrity and availability of industrial control systems, making it particularly concerning for sectors such as manufacturing, energy, and utilities where system reliability is paramount.
The exploitation of this vulnerability aligns with tactics described in the MITRE ATT&CK framework under the 'Execution' and 'Persistence' domains, where attackers can leverage buffer overflow vulnerabilities to execute arbitrary code and establish persistent access to compromised systems. Organizations using affected versions of Advantech/BroadWin WebAccess should immediately implement mitigations including updating to version 7.0 or later, which contains the necessary patches to address the buffer overflow condition. Network segmentation and access controls should be implemented to limit exposure, while ActiveX controls should be disabled in web browsers where possible. Additionally, regular security assessments and vulnerability scanning should be conducted to identify and remediate similar issues in industrial control system components, as this vulnerability demonstrates the ongoing risk of insecure coding practices in industrial automation software.