Ignore Erroneous or Unwanted Queries

中级别 1自动化bind

说明

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).

检查方式

审计方法: Shell 命令

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'

预期输出: compliant

修复方式

修复方法: 操作指南或基础设施补丁

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; };

属性

操作系统: 任意
标签: binddnsaccess-control
参考: CIS ISC BIND DNS Server 9.11 Benchmark v1.0.0 - 3.1 Ignore Erroneous or Unwanted Queries

检查本机

请在您有权审计的机器上运行此命令。扫描为只读操作。

shell

tmaegis scan --target bind