CVE-2020-0606 in .NET Core
Summary
by MITRE
A remote code execution vulnerability exists in .NET software when the software fails to check the source markup of a file.An attacker who successfully exploited the vulnerability could run arbitrary code in the context of the current user, aka '.NET Framework Remote Code Execution Vulnerability'. This CVE ID is unique from CVE-2020-0605.
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Analysis
by VulDB Data Team • 03/21/2024
The vulnerability described in CVE-2020-0606 represents a critical remote code execution flaw within Microsoft .NET Framework implementations that stems from inadequate validation of source markup in processed files. This weakness allows attackers to potentially execute malicious code with the privileges of the current user account, making it particularly dangerous in enterprise environments where .NET applications are extensively deployed. The vulnerability specifically affects how the framework handles markup parsing, creating an attack surface where malformed or specially crafted input can bypass security checks and lead to unauthorized code execution.
This vulnerability manifests as a failure in input validation mechanisms within the .NET Framework's markup processing components, which aligns with CWE-20 - Improper Input Validation and CWE-119 - Improper Restriction of Operations within a Sphere of Influence. The flaw operates by allowing attackers to manipulate the markup content of files that the framework processes, potentially causing the system to execute unintended code sequences. The vulnerability's impact is amplified by its remote exploitation capability, meaning attackers do not require local access to the target system to exploit the flaw. This characteristic places the vulnerability within the ATT&CK framework's T1203 - Exploitation for Client Execution category, where adversaries leverage application vulnerabilities to execute malicious code remotely.
The operational impact of CVE-2020-0606 extends beyond simple code execution as it provides attackers with the ability to escalate privileges and potentially move laterally within networks. When exploited successfully, the vulnerability allows adversaries to run code with the same permissions as the affected user account, which could lead to full system compromise if the account has elevated privileges. The vulnerability affects multiple versions of the .NET Framework and is particularly concerning because .NET Framework installations are prevalent across Windows environments, making the attack surface substantial. Organizations running web applications, services, or desktop applications that utilize .NET Framework components are all at risk, including those using technologies such as ASP.NET, Windows Forms, and WPF applications.
Mitigation strategies for this vulnerability should include immediate deployment of Microsoft security patches and updates, which address the underlying markup validation issues. Organizations should also implement network segmentation and access controls to limit the potential impact of successful exploitation attempts. Additional defensive measures include monitoring for unusual file processing activities and implementing application whitelisting policies to restrict execution of unauthorized code. The vulnerability's classification as a remote code execution flaw underscores the importance of maintaining current security patches and implementing robust security monitoring solutions. Organizations should also consider conducting vulnerability assessments to identify systems running affected .NET Framework versions and prioritize remediation efforts accordingly. Security teams should monitor for indicators of compromise related to this vulnerability, including unexpected code execution patterns and unusual network connections that may indicate exploitation attempts.