Nest is a framework for building scalable Node.js server-side applications. In versions 0.2.0 and below, a critical Remote Code Execution (RCE) vulnerability was discovered in the @nestjs/devtools-integration package. When enabled, the package exposes a local development HTTP server with an API endpoint that uses an unsafe JavaScript sandbox (safe-eval-like implementation). Due to improper sandboxing and missing cross-origin protections, any malicious website visited by a developer can execute arbitrary code on their local machine. The package adds HTTP endpoints to a locally running NestJS development server. One of these endpoints, /inspector/graph/interact, accepts JSON input containing a code field and executes the provided code in a Node.js vm.runInNewContext sandbox. This is fixed in version 0.2.1.
The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component.