CVE-2020-1374 in Windows
Summary
by MITRE
A remote code execution vulnerability exists in the Windows Remote Desktop Client when a user connects to a malicious server, aka 'Remote Desktop Client Remote Code Execution Vulnerability'.
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Analysis
by VulDB Data Team • 10/30/2020
The vulnerability identified as CVE-2020-1374 represents a critical remote code execution flaw within the Windows Remote Desktop Client component that enables attackers to execute arbitrary code on affected systems. This vulnerability specifically manifests when a user establishes a connection to a maliciously configured Remote Desktop Protocol server, creating a dangerous attack vector that can be exploited without user interaction beyond the initial connection attempt. The flaw exists in the client-side processing of Remote Desktop Protocol connections, making it particularly concerning for enterprise environments where Remote Desktop Services are commonly deployed. Security researchers have classified this vulnerability as highly dangerous due to its ability to bypass traditional security controls and execute malicious payloads directly on target systems.
The technical root cause of CVE-2020-1374 stems from insufficient input validation within the Remote Desktop Client's handling of connection parameters and server responses. When the client processes data from a compromised Remote Desktop server, it fails to properly validate the integrity of incoming data structures, allowing attackers to craft specially malformed responses that trigger buffer overflow conditions or other memory corruption vulnerabilities. This type of flaw aligns with CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which addresses heap-based buffer overflow scenarios. The vulnerability demonstrates characteristics consistent with the attack pattern described in the MITRE ATT&CK framework under T1210 - Exploitation of Remote Services, where adversaries leverage weaknesses in network services to gain unauthorized access and execute code on target systems.
The operational impact of this vulnerability extends beyond simple code execution, as it provides attackers with a pathway to establish persistent access to enterprise networks through the Remote Desktop protocol. Organizations that rely heavily on Remote Desktop Services for remote work or system administration are particularly vulnerable, as the attack requires minimal user interaction beyond connecting to a malicious server. The vulnerability can be exploited across various Windows operating systems including Windows 10, Windows Server 2016, and Windows Server 2019, making it a widespread concern for enterprise security teams. Additionally, the vulnerability's exploitation does not require authentication or elevated privileges, which means that even users with standard accounts could potentially be compromised. This characteristic makes the vulnerability particularly dangerous for environments where Remote Desktop is enabled for legitimate business purposes but may not be properly secured or monitored.
Mitigation strategies for CVE-2020-1374 should focus on immediate patch deployment through Microsoft's regular security updates, as well as network-level controls to prevent unauthorized Remote Desktop connections. Organizations should implement network segmentation to isolate Remote Desktop services from critical systems and deploy intrusion detection systems to monitor for suspicious Remote Desktop protocol traffic patterns. Security teams should also consider disabling Remote Desktop services where they are not essential for business operations and enforce strict access controls for legitimate Remote Desktop usage. The vulnerability's characteristics align with ATT&CK technique T1071.004, which covers application layer protocol usage for remote access, making it essential for security operations centers to monitor and analyze Remote Desktop protocol communications for signs of exploitation attempts. Regular security assessments and vulnerability scanning should include checks for exposed Remote Desktop services to identify and remediate potential exposure points.