rbash - Restricted Bash

rbash is a shell available on Linux systems.
It's a variant of Bash (restricted mode bash) that restricts user actions.

Restrictions

When rbash is invoked, it disallows certain things:

• Disallows changing $PATH, $SHELL, $BASH_ENV.
• Disallows using cd, exec, set +r, and unset of certain vars.
• Disallows using redirection (redirecting output anywhere).