Description
react-dev-utils prior to v11.0.4 exposes a function, getProcessForPort, where an input argument is concatenated into a command string to be executed. This function is typically used from react-scripts (in Create React App projects), where the usage is safe. Only when this function is manually invoked with user-provided values (ie: by custom code) is there the potential for command injection. If you're consuming it from react-scripts then this issue does not affect you.
Remediation
References
https://github.com/facebook/create-react-app/pull/10644
https://www.facebook.com/security/advisories/cve-2021-24033