Nuclio is a "Serverless" framework for Real-Time Events and Data Processing. Prior to version 1.15.20, the Nuclio Shell Runtime component contains a command injection vulnerability in how it processes user-supplied arguments. When a function is invoked via HTTP, the runtime reads the X-Nuclio-Arguments header and directly incorporates its value into shell commands without any validation or sanitization. This issue has been patched in version 1.15.20.