Do Not Define a Static Source Port

보통레벨 1자동bind

설명

BIND can be configured to always use the same source port when communicating with other DNS servers. This capability is made possible through the query-source port option, and the query-source-v6 port option. It is recommended that the source port be omitted if the query-source option is used, or that the port be specified as a *, so that the port will not be a static port ... The audit fails when any query-source or query-source-v6 statement sets a fixed port (port * / port 0 is allowed). The audit parses the effective configuration printed by named-checkconf -p (all include files resolved) from /etc/named.conf (RHEL; chroot /var/named/chroot is detected) or /etc/bind/named.conf (Debian/Ubuntu).

점검 방법

감사 방식: 셸 명령

shell

if [ -f /var/named/chroot/etc/named.conf ]; then out=$(named-checkconf -t /var/named/chroot -p /etc/named.conf 2>/dev/null) || exit 1
else conf=/etc/named.conf; [ -f "$conf" ] || conf=/etc/bind/named.conf
  out=$(named-checkconf -p "$conf" 2>/dev/null) || exit 1; fi
flat=$(printf '%s\n' "$out" | tr '\t\n' '  ' | tr -s ' ')
opts=$(printf '%s\n' "$out" | awk '/^options[ \t]*\{/{f=1} f{print} f&&/^\};/{exit}' | tr '\t\n' '  ' | tr -s ' ')
bad=$(printf '%s\n' "$flat" | grep -Eo 'query-source(-v6)? [^;]*;' | grep -E ' port [1-9][0-9]*')
[ -z "$bad" ] && echo compliant || { echo 'static query source port:'; printf '%s\n' "$bad"; }

예상 출력: compliant

조치 방법

조치 방식: 가이드 또는 인프라 패치

Either remove the port specification from the query-source or the query-source-v6 option or use an * for the port number.

속성

운영 체제: 모두
태그: binddnsdnssec
참고 자료: CIS ISC BIND DNS Server 9.11 Benchmark v1.0.0 - 7.1 Do Not Define a Static Source Port

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감사 권한이 있는 시스템에서 실행하세요. 스캔은 읽기 전용입니다.

shell

tmaegis scan --target bind