TMA-BIND-3.1

Ignore Erroneous or Unwanted Queries

中レベル 1自動bind

説明

BIND can be configured to ignore requests originating from specified network segments. This is accomplished by implementing the blackhole option in named.conf. It is recommended that this feature be implemented to ignore requests that originate outside of expected network segments. The audit requires a non-empty blackhole address list in the global options. 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).

チェック方法

監査方法: シェルコマンド

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 ' ')
printf '%s\n' "$opts" | grep -Eq '[{; ]blackhole \{ *[^} ]' && echo compliant || echo 'no blackhole list in options'

期待される出力: compliant

修正方法

修正方法: ガイダンスまたは IaC パッチ

Add a blackhole option for multicast and link local addresses, and all private RFC 1918 addresses that are not being used. blackhole { // Private RFC 1918 addresses 10/8; 192.168/16; 172.16/12; // Multicast 224/8; // Link Local 169.254/16; };

プロパティ

オペレーティングシステム: すべて
タグ: binddnsaccess-control
参照: CIS ISC BIND DNS Server 9.11 Benchmark v1.0.0 - 3.1 Ignore Erroneous or Unwanted Queries

このホストをチェック

監査が許可されているマシンで実行してください。スキャンは読み取り専用です。

shell

tmaegis scan --target bind