CVE-2020-0605 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-2020-0606.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 03/21/2024
This vulnerability represents a critical remote code execution flaw in Microsoft .NET Framework that arises from insufficient validation of source markup within files processed by the software. The vulnerability stems from the framework's failure to properly validate or sanitize input markup, creating an attack surface where malicious code can be executed without proper authorization. The issue specifically affects how .NET Framework handles certain file types that contain markup content, allowing attackers to craft specially formatted files that bypass normal security checks. This flaw demonstrates a classic insufficient input validation weakness that has been classified under CWE-20, which encompasses various forms of input validation failures that can lead to code execution vulnerabilities.
The operational impact of this vulnerability extends beyond simple privilege escalation as it allows remote attackers to execute arbitrary code with the privileges of the current user account. This means that an attacker could potentially gain access to sensitive data, install malware, modify system configurations, or establish persistent access to affected systems. The vulnerability is particularly concerning because it can be exploited remotely without requiring authentication, making it an attractive target for automated attacks. The attack vector typically involves tricking users into opening malicious files or accessing compromised web content that triggers the vulnerable code path within the .NET Framework. This aligns with ATT&CK technique T1059.001 for command and script injection, where adversaries leverage application vulnerabilities to execute malicious code.
The exploitation of this vulnerability requires the attacker to craft specific markup content that will be processed by the vulnerable .NET Framework components. When the framework attempts to parse or render this malicious markup, the insufficient validation allows the embedded malicious code to execute within the context of the user's privileges. This creates a pathway for attackers to perform various malicious activities including data exfiltration, system reconnaissance, or privilege escalation. The vulnerability affects multiple versions of the .NET Framework, making it widespread across affected systems and increasing the potential attack surface. Security researchers have noted that the flaw can be particularly dangerous in enterprise environments where .NET Framework is extensively used for web applications and internal software solutions, as it provides attackers with a means to compromise multiple systems simultaneously.
Mitigation strategies should focus on immediate patching of affected .NET Framework versions to address the markup validation issues. Organizations should implement network segmentation and access controls to limit exposure of systems running vulnerable .NET Framework components. Additionally, security monitoring should be enhanced to detect suspicious file access patterns or unusual network activity that might indicate exploitation attempts. The implementation of application whitelisting policies can provide an additional layer of defense by restricting execution of unauthorized code. Regular security assessments and vulnerability scanning should be conducted to identify systems that may be running outdated or unpatched versions of the .NET Framework. Organizations should also consider implementing web application firewalls and content filtering solutions to prevent malicious markup from reaching vulnerable applications. The remediation process must include comprehensive testing to ensure that patches do not introduce compatibility issues with existing applications while maintaining the security posture against this specific remote code execution vulnerability.