Skip to content

PM2 is susceptable to inspector port attack through SIGUSR1 #6001

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
dreusel opened this issue Jun 5, 2025 · 0 comments
Open

PM2 is susceptable to inspector port attack through SIGUSR1 #6001

dreusel opened this issue Jun 5, 2025 · 0 comments

Comments

@dreusel
Copy link

dreusel commented Jun 5, 2025

By default Node.js will listen for SIGUSR1 and start its internal inspector when it is received. This creates a security risk on production systems as the inspector interface could be used to eavesdrop on RPC intractions, for example, and execute arbitrary code in general.
For example in our infrastructure we use a PM2 module to listen for apps starting/restarting and send them their 'secrets' (API/signing keys etc) through sendLineToStdin(). However if a bad actor would manage to get access to the system they could send SIGUSR1 to the PM2 God process, attach a debugger and set some breakpoints to intercept these transactions and therefore steal the secrets.

This can easily be prevented by registering a no-op handler for SIGUSR1, as is recommended in the Security best practices provided by the Node.js team: https://nodejs.org/en/learn/getting-started/security-best-practices.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

No branches or pull requests

1 participant