The default seccomp profile must not be disabled.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-260937	CNTR-MK-001170	SV-260937r966168_rule		Medium

Description
Seccomp filtering provides a means for a process to specify a filter for incoming system calls. The default seccomp profile works on a whitelist basis and allows 311 system calls, blocking all others. It must not be disabled unless it hinders the container application usage. The default seccomp profile blocks syscalls, regardless of --cap-add passed to the container. A large number of system calls are exposed to every user and process, with many of them going unused for the entire lifetime of the process. Most of the applications do not need all the system calls and thus benefit by having a reduced set of available system calls. The reduced set of system calls reduces the total kernel surface exposed to the application and thus improvises application security. When running a container, it uses the default profile unless it is overridden with the --security-opt option.

Description

Seccomp filtering provides a means for a process to specify a filter for incoming system calls. The default seccomp profile works on a whitelist basis and allows 311 system calls, blocking all others. It must not be disabled unless it hinders the container application usage. The default seccomp profile blocks syscalls, regardless of --cap-add passed to the container. A large number of system calls are exposed to every user and process, with many of them going unused for the entire lifetime of the process. Most of the applications do not need all the system calls and thus benefit by having a reduced set of available system calls. The reduced set of system calls reduces the total kernel surface exposed to the application and thus improvises application security. When running a container, it uses the default profile unless it is overridden with the --security-opt option.

STIG	Date
Mirantis Kubernetes Engine Security Technical Implementation Guide	2024-04-10

Details

Check Text ( C-64666r966166_chk )
When using Kubernetes orchestration, this check is Not Applicable. For Swarm orchestration, to ensure the default seccomp profile is not disabled, log in to the CLI: Linux: As an MKE Admin, execute the following command using a Universal Control Plane (MKE) client bundle: docker ps --quiet --filter "label=com.docker.ucp.version" \| xargs docker inspect --format '{{ .Id }}: SecurityOpt={{ .HostConfig.SecurityOpt }}' If seccomp:=unconfined, then the container is running without any seccomp profiles and this is a finding.

Check Text ( C-64666r966166_chk )

When using Kubernetes orchestration, this check is Not Applicable.

For Swarm orchestration, to ensure the default seccomp profile is not disabled, log in to the CLI:

Linux: As an MKE Admin, execute the following command using a Universal Control Plane (MKE) client bundle:

docker ps --quiet --filter "label=com.docker.ucp.version" | xargs docker inspect --format '{{ .Id }}: SecurityOpt={{ .HostConfig.SecurityOpt }}'

If seccomp:=unconfined, then the container is running without any seccomp profiles and this is a finding.

Fix Text (F-64574r966167_fix)
When using Kubernetes orchestration, this check is Not Applicable. When using Swarm orchestration, do not pass unconfined flags to run a container without the default seccomp profile. Refer to seccomp documentation for details: https://docs.docker.com/engine/security/seccomp/.