Skip to content
AI Security

Interview question · Systems, OS & Memory Safety

What are Linux capabilities, why is CAP_SYS_ADMIN called 'the new root', and how do you decide which capabilities a process gets?

Capabilities split root into pieces, but some pieces are nearly the whole thing. A strong answer knows the sets, the dangerous capabilities, and why 'drop all, add one' is the only defensible default.

mediumEssentialNewPreparation tags: Google, Amazon, MicrosoftUpdated Nov 2026

Capabilities split root into pieces, but some pieces are nearly the whole thing. A strong answer knows the sets, the dangerous capabilities, and why 'drop all, add one' is the only defensible default.

Make your first attempt

What would you say before reading the answer?

  1. 01 State the assumptions your answer depends on.
  2. 02 Explain the mechanism and choose a control.
  3. 03 Name a condition that would change your decision.

The worked answer includes an approach, scoring criteria and follow-up questions. Compare the reasoning with your own.

signing in unlocks more free answers per topic

What if · the follow-ups in this answer

The answer works through 6 follow-ups like an interviewer would

A container needs to bind to port 443, and the developer runs it as root to make that work.

  1. What are capabilities?
  2. What would you grant here?
  3. Which capabilities are dangerous?
  4. How are capabilities tracked?
  5. How would you verify the container's capabilities?
  6. What would you change?

Each rung has a nudge, a model answer, the principle that carries over and the weak answer to avoid. Sign in free to open it.

UP NEXT ON YOUR JOURNEY
Next in this trackDiscretionary versus mandatory access control: how do SELinux and AppArmor confine a process, and how do you handle a denial?Next in this trackWhat is a TOCTOU race, how does it turn into privilege escalation through files, and how do you write privileged code that avoids it?Next in this trackDesign privilege separation for a network-facing service, and explain how to drop privileges so they cannot be regained.
DISCUSSION · 0

No comments yet. Share a correction or a different way to answer it.