CVE-2002-0864 in Windows
Summary
by MITRE
The Remote Data Protocol (RDP) version 5.1 in Microsoft Windows XP allows remote attackers to cause a denial of service (crash) when Remote Desktop is enabled via a PDU Confirm Active data packet that does not set the Pattern BLT command, aka "Denial of Service in Remote Desktop."
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Analysis
by VulDB Data Team • 09/17/2018
The vulnerability described in CVE-2002-0864 represents a critical denial of service flaw within the Remote Desktop Protocol implementation of Microsoft Windows XP. This issue specifically affects RDP version 5.1 and exploits a weakness in how the system processes incoming data packets when Remote Desktop services are active. The vulnerability operates at the network protocol level, targeting the structured communication mechanisms that enable remote desktop connections between client and server systems.
The technical flaw manifests when the Remote Desktop server receives a PDU Confirm Active data packet that fails to properly initialize or set the Pattern BLT command within the packet structure. This command is essential for proper graphics handling in remote desktop sessions, and its absence creates a condition where the system's processing logic encounters an unexpected state. The flaw stems from insufficient input validation and error handling within the RDP protocol stack, where the server does not adequately validate the completeness or proper formatting of incoming protocol data packets before attempting to process them.
When exploited, this vulnerability allows remote attackers to crash the Remote Desktop service by sending specifically crafted malformed packets that bypass normal protocol validation mechanisms. The system's failure to properly handle the missing Pattern BLT command results in an unhandled exception that terminates the RDP service process, effectively rendering the remote desktop functionality unavailable to legitimate users. This creates a denial of service condition that can be exploited by any remote attacker with network access to the target system, making it particularly dangerous in enterprise environments where remote desktop services are commonly enabled.
The operational impact of CVE-2002-0864 extends beyond simple service disruption as it represents a fundamental weakness in Microsoft's remote access infrastructure. Organizations relying on Windows XP systems with enabled Remote Desktop services face significant risk of unauthorized service disruption, potentially affecting business continuity and remote work capabilities. The vulnerability's exploitability from remote locations without authentication requirements makes it particularly attractive to threat actors seeking to disrupt operations or create cover for more sophisticated attacks. This flaw aligns with ATT&CK technique T1499.004 for network denial of service and demonstrates the importance of proper protocol validation in network services.
Security professionals should recognize this vulnerability as a classic example of insufficient input validation, which corresponds to CWE-20, and the improper handling of protocol states that leads to service termination. The remediation approach involves applying Microsoft security patches that address the protocol validation logic and ensure proper handling of malformed packets. Additionally, organizations should implement network segmentation to limit access to Remote Desktop services, disable unnecessary Remote Desktop functionality, and deploy network monitoring solutions to detect anomalous packet patterns that may indicate exploitation attempts. The vulnerability underscores the critical need for robust protocol handling and input validation in network services, particularly those providing remote access capabilities that are essential for enterprise operations.