iOS Simulator MCP Server (ios-simulator-mcp) is a Model Context Protocol (MCP) server for interacting with iOS simulators. Versions prior to 1.3.3 are written in a way that is vulnerable to command injection vulnerability attacks as part of some of its MCP Server tool definition and implementation. The MCP Server exposes the tool `ui_tap` which relies on Node.js child process API `exec` which is an unsafe and vulnerable API if concatenated with untrusted user input. LLM exposed user input for `duration`, `udid`, and `x` and `y` args can be replaced with shell meta-characters like `;` or `&&` or others to change the behavior from running the expected command `idb` to another command. When LLMs are tricked through prompt injection (and other techniques and attack vectors) to call the tool with input that uses special shell characters such as `; rm -rf /tmp;#` and other payload variations, the full command-line text will be interepted by the shell and result in other commands except of `ps` executing on the host running the MCP Server. Version 1.3.3 contains a patch for the issue.