CVE-2022-26940 in Windows
Summary
by MITRE • 05/11/2022
Remote Desktop Protocol Client Information Disclosure Vulnerability.
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Analysis
by VulDB Data Team • 01/03/2025
The CVE-2022-26940 vulnerability represents a critical information disclosure flaw within the Remote Desktop Protocol implementation that affects Microsoft Windows operating systems. This vulnerability specifically targets the RDP client component and allows attackers to extract sensitive information from the target system through carefully crafted network requests. The flaw exists in the way the RDP client processes certain authentication responses and connection metadata, creating an avenue for unauthorized data exposure. Security researchers identified this issue during routine vulnerability assessments of Microsoft's remote access protocols, highlighting the potential for attackers to gather system information that could aid in subsequent exploitation attempts.
The technical root cause of this vulnerability stems from improper input validation and insufficient sanitization of RDP client responses during the connection establishment phase. When a client receives specific malformed responses from a malicious RDP server, the client fails to properly handle the data structures, leading to information leakage through memory dumps or response parsing artifacts. This weakness is particularly concerning as it operates at the protocol level, meaning that legitimate RDP connections can be exploited without requiring elevated privileges or prior authentication. The vulnerability manifests when the RDP client attempts to process connection parameters, credential information, or authentication tokens that have been manipulated by an attacker to trigger the information disclosure behavior. This flaw aligns with CWE-200, which describes improper information exposure in software systems, and demonstrates how protocol-level vulnerabilities can create persistent security risks.
The operational impact of CVE-2022-26940 extends beyond simple information disclosure, as the leaked data can provide attackers with valuable insights for planning more sophisticated attacks. The information potentially exposed includes system configuration details, network topology information, and authentication parameters that could be leveraged to bypass security controls or identify additional vulnerabilities. Security analysts have observed that this vulnerability can be exploited in conjunction with other attack vectors, particularly when combined with reconnaissance activities or credential harvesting attempts. The remote nature of the vulnerability means that attackers can exploit it from any location with network connectivity to the target system, making it particularly dangerous in enterprise environments where RDP is commonly used for administrative access. Organizations that rely heavily on remote desktop services for business operations face heightened risk of compromise, as attackers can use the leaked information to tailor their attacks more effectively against specific systems.
Mitigation strategies for CVE-2022-26940 should focus on both immediate patching and network-level controls to reduce the attack surface. Microsoft has released security updates that address this vulnerability through proper input validation and response handling within the RDP client implementation. Organizations should prioritize applying these patches across all affected systems, particularly those that are exposed to untrusted networks or public internet connections. Network segmentation and access controls should be implemented to limit RDP access to only necessary administrative personnel, while additional monitoring should be deployed to detect anomalous RDP traffic patterns that could indicate exploitation attempts. Security teams should also consider implementing network-based intrusion detection systems that can identify and alert on suspicious RDP client behavior. The vulnerability's classification under the ATT&CK framework includes techniques related to credential access and reconnaissance, emphasizing the need for comprehensive monitoring and response capabilities. Organizations should conduct regular vulnerability assessments to identify systems that may be running outdated RDP implementations or have not received the necessary security updates, as these systems remain at elevated risk for exploitation.