CVE-2009-0090 in Windows
Summary
by MITRE
Microsoft .NET Framework 1.0 SP3, 1.1 SP1, and 2.0 SP1 does not properly validate .NET verifiable code, which allows remote attackers to obtain unintended access to stack memory, and execute arbitrary code, via (1) a crafted XAML browser application (XBAP), (2) a crafted ASP.NET application, or (3) a crafted .NET Framework application, aka "Microsoft .NET Framework Pointer Verification Vulnerability."
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Analysis
by VulDB Data Team • 09/18/2018
The Microsoft .NET Framework vulnerability identified as CVE-2009-0090 represents a critical security flaw in the framework's code verification mechanisms that affects versions 1.0 SP3, 1.1 SP1, and 2.0 SP1. This vulnerability stems from insufficient validation of .NET verifiable code, creating a pathway for malicious actors to exploit memory access patterns within the runtime environment. The flaw specifically targets the pointer verification processes that are fundamental to ensuring code safety and preventing unauthorized memory operations within the .NET execution environment.
The technical exploitation of this vulnerability occurs through three distinct attack vectors that leverage different application types within the .NET ecosystem. Attackers can craft malicious XAML browser applications (XBAP) that, when executed, bypass the normal verification procedures and gain access to stack memory locations that should remain protected. Similarly, malicious ASP.NET applications can be constructed to exploit the same verification gap, while specially crafted .NET Framework applications can directly manipulate memory structures. This multi-vector approach increases the attack surface and makes the vulnerability particularly dangerous as it can be exploited across different deployment scenarios within the .NET environment. The vulnerability is classified under CWE-119 in the Common Weakness Enumeration, which specifically addresses weaknesses in memory safety and improper access to memory locations.
The operational impact of this vulnerability is severe and far-reaching, as it allows remote attackers to execute arbitrary code on affected systems with the privileges of the executing process. This capability enables attackers to gain unauthorized access to sensitive information, modify system behavior, and potentially establish persistent access to compromised environments. The vulnerability particularly affects enterprise environments where .NET Framework applications are commonly deployed, as it can be exploited through web browsers, web applications, and desktop applications that utilize the affected framework versions. Organizations running these older framework versions face significant risk of compromise, as the vulnerability can be exploited without requiring any user interaction beyond visiting a malicious web page or executing a crafted application.
Mitigation strategies for CVE-2009-0090 primarily involve immediate patching of affected systems with the security updates provided by Microsoft, as well as implementing network-level protections to prevent access to potentially malicious applications. Organizations should prioritize updating to patched versions of the .NET Framework, with the latest available service packs and security updates. Additionally, network segmentation and application whitelisting can provide defense-in-depth measures to limit the potential impact of exploitation. The ATT&CK framework categorizes this vulnerability under the T1059 technique for Command and Scripting Interpreter, as the exploitation can lead to arbitrary code execution that may be used to establish further compromise. System administrators should also consider implementing monitoring for unusual memory access patterns and code execution behaviors that could indicate exploitation attempts. Given the age of the affected versions, organizations should also evaluate their application compatibility and plan for migration to supported .NET Framework versions to prevent similar vulnerabilities from affecting their environments.