Securely Authenticate Zone Transfers

高级别 2自动化bind

说明

A zone transfer is a mechanism commonly used by DNS deployments to replicate zone information from master/primary servers to slave/secondary servers. Each pair of name servers participating in zone transfers should authenticate the requests and ensure the integrity of the responses by using a unique shared secret TSIG key. The audit requires at least one allow-transfer statement and that every allow-transfer list (options and zones) contains only none or key <name> entries; any, IP addresses and ACL names fail. 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' "$flat" | grep -Eq '(^|[ ;{])allow-transfer \{' || { echo 'no allow-transfer statement'; exit 1; }
bad=$(printf '%s\n' "$flat" | grep -Eo '(^|[ ;{])allow-transfer \{[^}]*\}' | sed 's/.*allow-transfer {//; s/}$//' | tr ';' '\n' | sed 's/^ *//; s/ *$//' | grep -v '^$' | grep -Eiv '^("?none"?|key "?[^ "]+"?)$')
[ -z "$bad" ] && echo compliant || { echo 'allow-transfer entries not allowed:'; printf '%s\n' "$bad" | sort -u; }

预期输出: compliant

修复方式

修复方法: 操作指南或基础设施补丁

Generate TSIG keys 256 bits in length, unique for each host-to-host communication. Securely Transfer the keys and configure the keys to be required in all allow-transfer statements.

属性

操作系统: 任意
标签: binddnszone-transfer
参考: CIS ISC BIND DNS Server 9.11 Benchmark v1.0.0 - 5.1 Securely Authenticate Zone Transfers

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 --level 2