CVE-2008-4252 in Visual Basic
Summary
by MITRE
The DataGrid ActiveX control in Microsoft Visual Basic 6.0 and Visual FoxPro 8.0 SP1 and 9.0 SP1 and SP2 does not properly handle errors during access to incorrectly initialized objects, which allows remote attackers to execute arbitrary code via a crafted HTML document, related to corruption of the "system state," aka "DataGrid Control Memory Corruption Vulnerability."
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Analysis
by VulDB Data Team • 08/21/2019
The CVE-2008-4252 vulnerability represents a critical memory corruption flaw within Microsoft's DataGrid ActiveX control that affects multiple versions of Visual Basic 6.0 and Visual FoxPro 8.0 SP1 through 9.0 SP2. This vulnerability operates at the core of how the ActiveX control manages object initialization and error handling, creating a dangerous condition where malformed input can trigger unexpected system behavior. The flaw specifically manifests when the control attempts to access incorrectly initialized objects during HTML document processing, leading to potential code execution in the context of the user's privileges. This vulnerability is particularly concerning because it leverages the widespread use of ActiveX controls in web environments and the trusted nature of Microsoft development tools within enterprise networks.
The technical implementation of this vulnerability stems from improper error handling mechanisms within the DataGrid ActiveX control's object lifecycle management. When a crafted HTML document attempts to interact with an improperly initialized DataGrid object, the control fails to properly validate or sanitize the access patterns, resulting in memory corruption that can be exploited to overwrite critical system memory locations. This memory corruption directly relates to CWE-121, which describes heap-based buffer overflow conditions, and CWE-125, which covers out-of-bounds read vulnerabilities. The flaw essentially allows attackers to manipulate the control's internal state through carefully constructed malicious input that triggers memory corruption during object access operations.
The operational impact of this vulnerability extends beyond simple code execution to encompass significant security implications for enterprise environments where Visual Basic and Visual FoxPro applications are prevalent. Attackers can leverage this vulnerability to execute arbitrary code with the privileges of the logged-on user, potentially leading to complete system compromise, data exfiltration, or lateral movement within networks. The vulnerability's exploitation vector through HTML documents makes it particularly dangerous in web-based attack scenarios, where users may unknowingly encounter malicious content through email attachments, compromised websites, or social engineering campaigns. This makes the vulnerability particularly attractive to threat actors seeking to establish persistent access to target networks.
Organizations should implement multiple layers of defense to mitigate this vulnerability, beginning with immediate patching of affected systems and disabling ActiveX controls in web browsers where possible. The mitigation strategy should align with ATT&CK technique T1173, which covers the use of external remote services, by implementing network segmentation and access controls to limit exposure. Additionally, security teams should deploy application whitelisting solutions to prevent execution of untrusted ActiveX components and monitor for suspicious ActiveX control usage patterns. Regular security assessments should focus on identifying legacy Visual Basic and Visual FoxPro applications that may be running in production environments, as these systems often represent significant attack surface areas. The vulnerability also underscores the importance of maintaining up-to-date security patches for development tools and runtime environments, as this flaw affects components that are integral to many enterprise applications and development workflows.