CVE-2020-0612 in Windows
Summary
by MITRE
A denial of service vulnerability exists in Windows Remote Desktop Gateway (RD Gateway) when an attacker connects to the target system using RDP and sends specially crafted requests, aka 'Windows Remote Desktop Gateway (RD Gateway) Denial of Service Vulnerability'.
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Analysis
by VulDB Data Team • 03/21/2024
The vulnerability identified as CVE-2020-0612 represents a critical denial of service weakness within the Windows Remote Desktop Gateway component that forms part of Microsoft's remote access infrastructure. This flaw specifically impacts systems configured with RD Gateway functionality, which serves as a secure gateway for remote desktop connections to internal networks. The vulnerability stems from insufficient input validation within the RDP protocol handling mechanisms of the RD Gateway service, creating an exploitable condition where malformed or specially crafted RDP requests can trigger system instability.
The technical exploitation of this vulnerability occurs when an unauthenticated attacker establishes a connection to the target RD Gateway server using the Remote Desktop Protocol and subsequently sends malformed packets that exploit buffer handling inconsistencies in the gateway's processing logic. This flaw operates at the protocol level where the RD Gateway service fails to properly validate incoming RDP traffic before attempting to process it, leading to memory corruption or resource exhaustion conditions that ultimately result in service disruption. The vulnerability is classified under CWE-121 as a stack-based buffer overflow condition, though the specific implementation manifests as a denial of service rather than arbitrary code execution.
From an operational perspective, this vulnerability poses significant risk to organizations that rely on RD Gateway for remote access management, as successful exploitation can result in complete service unavailability for legitimate users. The impact extends beyond simple service interruption since RD Gateway typically serves as a critical access point for remote workforce connectivity, IT management, and administrative functions. Organizations may experience extended downtime during incident response, potential business disruption, and increased operational overhead as security teams work to contain the vulnerability and implement mitigations. The vulnerability affects multiple Windows Server versions including Windows Server 2016, Windows Server 2019, and various Windows 10 editions that have RD Gateway functionality enabled.
The attack vector for this vulnerability requires minimal privileges and can be executed remotely without authentication, making it particularly dangerous for organizations with exposed RD Gateway services on public networks. According to ATT&CK framework category T1190, this represents a network service exploitation technique where adversaries leverage protocol-level weaknesses to disrupt services. Mitigation strategies include immediate deployment of Microsoft security patches, implementing network segmentation to restrict RD Gateway access, configuring firewall rules to limit RDP traffic to trusted sources, and monitoring for anomalous RDP connection patterns. Additionally, organizations should consider disabling RD Gateway functionality if not required, implementing intrusion detection systems to monitor for exploitation attempts, and maintaining comprehensive incident response procedures that account for remote access service disruptions. The vulnerability underscores the importance of proper input validation and robust error handling in network service implementations, particularly those handling protocols with complex state management like RDP.