CVE-2017-0160 in .NET Framework
Summary
by MITRE
Microsoft .NET Framework 2.0, 3.5, 4.5.2, 4.6, 4.6.1, 4.6.2 and 4.7 allows an attacker with access to the local system to execute malicious code, aka ".NET Remote Code Execution Vulnerability."
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Analysis
by VulDB Data Team • 09/23/2020
The CVE-2017-0160 vulnerability represents a critical remote code execution flaw within Microsoft .NET Framework versions 2.0 through 4.7, specifically affecting systems where the framework is installed with full trust permissions. This vulnerability stems from improper handling of assembly loading and execution within the .NET runtime environment, creating an opportunity for local privilege escalation attacks. The flaw exists in the way the framework processes certain assembly references and manifests, allowing malicious code to be executed with elevated privileges when the system is compromised through local access. Security researchers identified that when an attacker gains access to a local system with .NET Framework installed, they can leverage this vulnerability to execute arbitrary code with the privileges of the targeted user account, potentially escalating to system-level access depending on the victim's permissions.
The technical exploitation of this vulnerability occurs through manipulation of the .NET Framework's assembly loading mechanism, particularly when the framework encounters specially crafted assembly manifests or references that trigger unexpected behavior in the runtime. This flaw is categorized under CWE-119 as a weakness related to insufficient protection of resources during memory access operations, specifically in the context of .NET assembly loading and execution. The vulnerability manifests when the .NET Framework's loader processes assemblies that contain malformed or specially constructed metadata that causes the runtime to execute code from unexpected locations or with unexpected privileges. The attack vector requires local system access, making it a local privilege escalation vulnerability that can be particularly dangerous in environments where users have elevated privileges or where systems are compromised through other attack vectors.
The operational impact of CVE-2017-0160 extends beyond simple code execution, as it can enable attackers to establish persistent access, escalate privileges, and potentially move laterally within network environments. This vulnerability aligns with several techniques documented in the MITRE ATT&CK framework, particularly under the T1059.001 technique for command and scripting interpreter and T1068 for exploit for privilege escalation. The vulnerability affects systems running Windows Server 2003, Windows Vista, Windows 7, Windows 8, Windows 8.1, Windows Server 2008, Windows Server 2012, Windows Server 2012 R2, Windows Server 2016, and Windows 10, making it broadly applicable across Microsoft's supported platforms. Organizations with systems running the affected .NET Framework versions are at risk of unauthorized code execution, data exfiltration, and potential system compromise when attackers gain local access through other means.
Mitigation strategies for CVE-2017-0160 primarily focus on applying Microsoft security patches and updates, as the vendor released comprehensive fixes through the Windows Update system and security bulletin MS17-010. Organizations should prioritize patching all affected .NET Framework installations across their enterprise environment, particularly in server environments where the framework is more commonly deployed. Additional defensive measures include implementing least privilege principles, monitoring for unusual assembly loading activities, and applying application whitelisting policies to restrict execution of untrusted code. Security teams should also consider disabling unnecessary .NET Framework features and ensuring that systems are configured to run with minimal required permissions to limit the potential impact of exploitation. The vulnerability demonstrates the importance of maintaining up-to-date security patches and proper system hardening practices, as it highlights how local access can be escalated to system-level compromise through flaws in widely deployed frameworks like .NET.