CVE-2014-1806 in .NET Framework
Summary
by MITRE
The .NET Remoting implementation in Microsoft .NET Framework 1.1 SP1, 2.0 SP2, 3.5, 3.5.1, 4, 4.5, and 4.5.1 does not properly restrict memory access, which allows remote attackers to execute arbitrary code via vectors involving malformed objects, aka "TypeFilterLevel Vulnerability."
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Analysis
by VulDB Data Team • 12/20/2024
The CVE-2014-1806 vulnerability represents a critical security flaw in Microsoft .NET Framework implementations that affects versions spanning from 1.1 SP1 through 4.5.1. This vulnerability specifically targets the .NET Remoting subsystem which facilitates communication between distributed applications and enables objects to interact across application domain boundaries. The flaw manifests through improper memory access restrictions that create opportunities for malicious exploitation, making it particularly dangerous in networked environments where remote code execution capabilities can be leveraged by attackers. The vulnerability is categorized under CWE-119 in the Common Weakness Enumeration system, which identifies weaknesses related to improper restriction of operations within a memory buffer, directly linking to the memory access control issues present in the affected .NET Framework versions.
The technical exploitation of this vulnerability occurs through the manipulation of TypeFilterLevel settings within the .NET Remoting infrastructure. Attackers can craft malformed objects that bypass the intended security boundaries of the remoting system, allowing them to execute arbitrary code on affected systems. This occurs because the framework fails to properly validate object serialization and deserialization processes, particularly when handling remote method invocations. The vulnerability enables attackers to exploit the trust relationships that exist within .NET Remoting configurations, where objects are expected to be properly validated before processing. When TypeFilterLevel is set to Full or Medium, the system becomes vulnerable to attacks that can leverage the remoting infrastructure to execute malicious payloads without proper authorization. The attack vector specifically targets the deserialization process where untrusted data is converted into executable objects, creating a direct pathway for code execution.
The operational impact of CVE-2014-1806 extends beyond simple code execution to encompass complete system compromise and potential lateral movement within network environments. Systems running affected .NET Framework versions become vulnerable to remote code execution attacks that can be initiated from external networks, making them attractive targets for attackers seeking to establish persistent access or escalate privileges. The vulnerability affects both server and client configurations, meaning that any system involved in .NET Remoting communications could be compromised. Organizations with legacy applications that depend on .NET Remoting functionality face particular risk since these systems may not be easily updated or patched. The vulnerability's presence in multiple framework versions from 1.1 through 4.5.1 creates widespread exposure across enterprise environments where older applications may still be operational, particularly in government, financial, and industrial control systems that often maintain legacy infrastructure.
Mitigation strategies for CVE-2014-1806 focus primarily on implementing proper configuration changes and applying security updates from Microsoft. Organizations should immediately implement the security patches released by Microsoft as part of their regular security updates, which address the underlying memory access control issues in the .NET Remoting implementation. Configuration changes include setting TypeFilterLevel to Medium or High, which restricts the types of objects that can be deserialized and prevents many attack vectors. Security administrators should also consider disabling .NET Remoting functionality entirely if it is not required for business operations, as this eliminates the attack surface entirely. Network segmentation and firewall rules can help limit exposure by restricting access to systems running affected .NET Framework versions. The ATT&CK framework categorizes this vulnerability under T1059.007 for remote code execution through .NET and related technologies, highlighting the importance of monitoring and protecting these attack vectors. Additionally, organizations should implement runtime application self-protection measures and application whitelisting policies to prevent exploitation of similar vulnerabilities in the future.