CVE-2019-1108 in Windows
Summary
by MITRE
An information disclosure vulnerability exists when the Windows RDP client improperly discloses the contents of its memory, aka 'Remote Desktop Protocol Client Information Disclosure Vulnerability'.
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Analysis
by VulDB Data Team • 07/02/2020
The vulnerability identified as CVE-2019-1108 represents a critical information disclosure flaw within the Windows Remote Desktop Protocol client implementation that exposes sensitive memory contents to unauthorized parties. This vulnerability specifically affects the RDP client component responsible for establishing and maintaining remote desktop connections, creating a significant security risk for organizations relying on remote access solutions. The flaw manifests when the client application fails to properly sanitize memory operations during connection handling, potentially exposing confidential data including credentials, session information, and other sensitive operational details. According to the Common Weakness Enumeration framework, this vulnerability maps to CWE-200, which encompasses information exposure through improper handling of sensitive data within software applications. The vulnerability exists at the application layer where the RDP client processes incoming data and manages memory allocation for connection state information.
The technical exploitation of this vulnerability occurs when an attacker establishes a malicious RDP connection to a target system or when the vulnerable client application processes untrusted RDP server responses. The memory disclosure happens during the normal operation of the RDP client when it attempts to handle specific connection parameters or when processing certain types of RDP packets. Attackers can leverage this flaw to extract sensitive information from the client's memory space, potentially including authentication tokens, session keys, and other confidential data that would normally remain protected. The vulnerability does not require elevated privileges to exploit, making it particularly dangerous as it can be triggered through standard network communication channels. The attack vector aligns with the ATT&CK technique T1071.004 for application layer protocol usage and T1046 for network service scanning, as attackers can probe for vulnerable systems without requiring direct system compromise.
The operational impact of CVE-2019-1108 extends beyond simple data exposure, as the leaked information could enable more sophisticated attacks including credential theft, session hijacking, and lateral movement within network environments. Organizations utilizing RDP for remote access are particularly vulnerable, as the compromised client could provide attackers with sufficient information to conduct further reconnaissance or establish persistent access to target systems. The vulnerability affects multiple Windows versions including Windows 10, Windows Server 2016, and Windows Server 2019, creating widespread exposure across enterprise environments. Memory disclosure vulnerabilities of this nature can also facilitate privilege escalation attacks when the leaked information includes administrative credentials or system-level access tokens. The security implications are compounded by the fact that the vulnerability can be exploited through legitimate network traffic, making detection and prevention particularly challenging for security operations teams.
Mitigation strategies for this vulnerability should include immediate deployment of Microsoft security patches, which address the underlying memory handling issues in the RDP client implementation. Organizations should implement network segmentation to limit RDP access to authorized personnel only, and consider deploying additional authentication controls such as multi-factor authentication to reduce the impact of credential exposure. Network monitoring solutions should be configured to detect anomalous RDP traffic patterns that might indicate exploitation attempts, while endpoint detection and response tools should be tuned to identify memory access anomalies associated with the vulnerable client behavior. The vulnerability demonstrates the importance of secure coding practices and proper memory management in client applications, particularly those handling network communications and authentication data. Security teams should also consider implementing zero-trust network architectures that minimize the attack surface for RDP-based access and ensure that any compromised client cannot be used to pivot to other systems within the network. Regular vulnerability assessments and penetration testing should include specific checks for RDP client vulnerabilities to ensure comprehensive protection against similar disclosure flaws.