CVE-2014-4073 in .NET Framework
Summary
by MITRE
Microsoft .NET Framework 2.0 SP2, 3.5, 3.5.1, 4, 4.5, 4.5.1, and 4.5.2 processes unverified data during interaction with the ClickOnce installer, which allows remote attackers to gain privileges via vectors involving Internet Explorer, aka ".NET ClickOnce Elevation of Privilege Vulnerability."
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Analysis
by VulDB Data Team • 02/22/2022
The vulnerability identified as CVE-2014-4073 represents a critical elevation of privilege flaw within Microsoft .NET Framework versions spanning from 2.0 SP2 through 4.5.2. This weakness specifically manifests in the ClickOnce deployment mechanism, which is designed to enable users to install and run applications from the internet without requiring administrator privileges. The vulnerability arises from insufficient validation of data provided by remote sources during the ClickOnce installation process, creating a pathway for malicious actors to exploit the system's trust model and execute code with elevated privileges.
The technical nature of this vulnerability stems from the improper handling of unverified data within the ClickOnce installer component of the .NET Framework. When users interact with ClickOnce applications, the system processes metadata and configuration files that are downloaded from remote servers. The flaw occurs because the framework fails to adequately validate the integrity and authenticity of these components before executing them. This allows attackers to craft malicious ClickOnce manifests that, when executed through Internet Explorer, can bypass normal security boundaries and escalate privileges to SYSTEM level access.
The operational impact of this vulnerability is severe as it enables remote code execution with elevated privileges, potentially allowing attackers to compromise entire systems. The attack vector through Internet Explorer means that users can be exploited simply by visiting malicious websites or opening specially crafted email attachments containing ClickOnce applications. Once exploited, the vulnerability provides attackers with the ability to install malicious software, modify system files, access sensitive data, and establish persistent access to the compromised systems. This makes the vulnerability particularly dangerous in enterprise environments where users may have varying levels of system access.
From a cybersecurity framework perspective, this vulnerability maps directly to CWE-20, which describes improper input validation, and aligns with ATT&CK technique T1068, which covers "Exploitation for Privilege Escalation." The vulnerability also demonstrates characteristics of privilege escalation through application misconfiguration and trust boundary violations. Organizations should implement immediate mitigations including applying the relevant Microsoft security updates, disabling ClickOnce functionality where possible, and implementing network-level controls to restrict access to potentially malicious ClickOnce applications. Additionally, user education regarding the risks of executing unsigned or untrusted applications from the internet remains crucial in defending against this type of exploitation. The vulnerability highlights the importance of secure coding practices and proper input validation in framework components that handle remote data processing, particularly those that operate with elevated privileges.