PACSgear PACS Scan 5.2.1 contains an unauthenticated remote code execution vulnerability that allows remote attackers to read and write arbitrary files by exploiting an exposed .NET Remoting TCP service on port 22222 via PGImageExchQueue.exe without any authentication requirement. Attackers can chain the arbitrary file write primitive with DLL hijacking in PGImageExchangeQueueSvc.exe, which loads missing DLLs such as CRYPTSP.DLL from the application directory, to achieve remote code execution as NT Authority\SYSTEM upon service restart.