Ensure LXD instances do not enable container nesting

보통레벨 2자동lxd

설명

security.nesting=true exposes /proc and /sys more widely and relaxes AppArmor so containers can run their own container runtimes, enlarging the escape surface. The audit loops over instances from "lxc list --format csv -c n" (default project) and fails if any expanded configuration sets security.nesting to a truthy value. Hosts that deliberately run Docker-in-LXD should document the exception.

점검 방법

감사 방식: 셸 명령

shell

lxc info >/dev/null 2>&1 || exit 1
names=$(lxc list --format csv -c n 2>/dev/null) || exit 1
bad=0
for n in $names; do
  cfg=$(lxc config show --expanded "$n" 2>/dev/null) || exit 1
  if printf '%s\n' "$cfg" | grep -Eiq '^[[:space:]]*security\.nesting:[[:space:]]*"?(true|1|yes|on)"?[[:space:]]*$'; then echo "nesting: $n"; bad=1; fi
done
[ "$bad" -eq 0 ] && echo compliant

예상 출력: compliant

조치 방법

조치 방식: 가이드 또는 인프라 패치

lxc config unset <instance> security.nesting (or remove it from the profile), then restart the instance. Move workloads that need nested containers to a VM instance (lxc launch --vm).

속성

운영 체제: 모두
태그: lxdcontainersisolation
참고 자료: CIS-style LXD hardening guidance - Container nesting (no CIS benchmark section; verify against your hardening standard)

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감사 권한이 있는 시스템에서 실행하세요. 스캔은 읽기 전용입니다.

shell

tmaegis scan --target lxd --level 2