CVE-2014-0295 in .NET Framework
Summary
by MITRE
VsaVb7rt.dll in Microsoft .NET Framework 2.0 SP2 and 3.5.1 does not implement the ASLR protection mechanism, which makes it easier for remote attackers to execute arbitrary code via a crafted web site, as exploited in the wild in February 2014, aka "VSAVB7RT ASLR Vulnerability."
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Analysis
by VulDB Data Team • 01/09/2025
The vulnerability identified as CVE-2014-0295 represents a critical security flaw in Microsoft .NET Framework versions 2.0 SP2 and 3.5.1 where the VsaVb7rt.dll component fails to implement Address Space Layout Randomization protection mechanisms. This weakness specifically affects the runtime environment used for executing Visual Basic scripts within the .NET framework, creating a predictable memory layout that adversaries can exploit to bypass security controls. The vulnerability was actively exploited in the wild during February 2014, demonstrating its real-world impact and the sophistication of the attack vectors employed by threat actors.
The technical implementation of this flaw stems from the absence of ASLR (Address Space Layout Randomization) protection within the VsaVb7rt.dll module, which is part of the Visual Studio Automation Runtime components. ASLR is a core operating system security feature designed to randomize the memory addresses where program components are loaded, making it significantly more difficult for attackers to predict memory locations for code execution. Without this protection, the memory layout of the vulnerable component remains static and predictable, enabling attackers to craft malicious payloads that can reliably exploit memory addresses to execute arbitrary code. This vulnerability directly maps to CWE-1009, which describes insufficient entropy in random number generators, and more specifically to CWE-676, which addresses the use of dangerous functions that can lead to code execution.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it allows remote attackers to execute arbitrary code on affected systems through web-based attacks. Attackers can leverage this weakness by hosting malicious websites that trigger the vulnerable VsaVb7rt.dll component, typically through Internet Explorer or other web browsers that execute .NET Framework components. The attack vector specifically targets systems running Microsoft .NET Framework 2.0 SP2 and 3.5.1 where the vulnerable DLL is present, making it particularly dangerous in enterprise environments where legacy .NET Framework versions are still in use. This vulnerability enables attackers to gain unauthorized access to systems, potentially leading to complete system compromise, data exfiltration, and lateral movement within networks.
Mitigation strategies for CVE-2014-0295 require immediate implementation of security patches from Microsoft, specifically targeting the .NET Framework updates that restore proper ASLR protection to the VsaVb7rt.dll module. Organizations should prioritize patching systems running affected .NET Framework versions, as the vulnerability has been exploited in real-world scenarios and represents a significant risk to system security. Additional defensive measures include implementing network-based protections such as web application firewalls, restricting access to potentially malicious websites, and monitoring for suspicious network activity that may indicate exploitation attempts. Security teams should also consider implementing application whitelisting policies to prevent execution of untrusted code, and conduct thorough vulnerability assessments to identify any remaining systems that may still be running vulnerable .NET Framework versions. The exploitability of this vulnerability aligns with ATT&CK technique T1059.007, which covers the use of Visual Basic scripts for execution, making it particularly relevant for organizations that may be targeted by advanced persistent threat groups utilizing these specific attack patterns.