A critical heap buffer overflow in the FreeRDP Windows client enables remote code execution when a user interacts with a malicious RDP server during a clipboard paste operation.

The vulnerability is a heap-based buffer overflow (CWE-122) within the clipboard virtual channel. It occurs because the client fails to validate the size of incoming CLIPRDR_FILE_CONTENTS_RESPONSE PDUs against allocated buffer space, allowing an unauthenticated attacker to corrupt heap memory.

This vulnerability carries a CVSS score of 9.4, indicating an extreme risk to workstation security. Successful exploitation leads to arbitrary code execution on the user's machine, potentially resulting in full system compromise, malware installation, or lateral movement within the corporate network. The requirement for user interaction (a paste operation) does not significantly reduce the risk in environments where users frequently interact with RDP sessions.

Immediate Action: Upgrade the FreeRDP Windows client to version 3.29.0 or later to apply the necessary bounds checking on clipboard response data.

Proactive Monitoring: Monitor endpoint logs for abnormal application crashes or unauthorized process spawning related to the FreeRDP client process.

Compensating Controls: If patching is delayed, consider disabling clipboard redirection via RDP group policies or connection settings to eliminate the primary attack vector.

Public Exploit Available: No (exploit_available: false)

The severity of this remote code execution vulnerability necessitates immediate action. IT administrators should deploy the 3.29.0 update across all Windows workstations running FreeRDP to prevent potential exploitation of the clipboard channel.