Scanning Is Not Enough
A clean image can still be exploited at runtime through a flaw in the running application. Runtime container security hardens the container and watches its behavior while it executes.
Reduce What a Container Can Do
- Run as a non root user so a breakout has fewer privileges.
- Drop Linux capabilities that the workload does not need.
- Use a read only filesystem so an attacker cannot modify code.
- Avoid privileged mode, which removes most isolation.
Each restriction shrinks what an attacker gains if the application is compromised.
Watch Behavior
A runtime sensor learns or is told what normal looks like and alerts on surprises.
- An unexpected shell spawning inside a container is suspicious.
- A new outbound connection to an unknown host may signal exfiltration.
- Writing to a path that should be read only is a red flag.
Isolation Matters
Containers share the host kernel, so a kernel exploit can escape. Stronger sandboxes add an extra boundary for untrusted workloads.
Key idea
Runtime container security drops root, removes unneeded capabilities, and uses read only filesystems while a sensor watches for anomalous behavior, limiting and detecting compromise after an image is running.