First things that I am trying to discover using pentest:

* Files permissions (are sensitive files in my Linux build secure from exploits)
* Are programs running under users (e.g., something running under root user hen it should not)

Is there any framework/tool that can be employed to discover weaknesses in the above two areas for an Embedded Linux devices?

P.S: Consider me beginner in the area of penetration testing. I am trying to discover basic vulnerabilities and to fix those.