CLIPRDR is the Remote Desktop Protocol (RDP) clipboard redirection channel. It carries clipboard formats and data between the client and the remote server so copy-and-paste works during a session. Although it looks like a convenience feature, it is also a parsing boundary: the client must decode messages received from the remote side and handle them safely.
In cyber security, CLIPRDR matters because any bug in its input handling can let a malicious RDP server send malformed clipboard data to the client. That can lead to memory corruption, crashes, and in some cases code execution if the parser mismanages buffer sizes or allocations. Defenders treat clipboard redirection as part of the attack surface, so patching clients, limiting connections to trusted servers, and disabling clipboard sharing when it is not needed are practical ways to reduce risk.