Restrict Queries of the Cache

中等級 1自動化bind

說明

The BIND option allow-query-cache may be used to restrict or allow BIND to provide answers to queries from the current cache of previously resolved queries. An authoritative only name server should not allow cache queries, except from the localhost, A caching only name server should allow cache queries only from the list of authorized networks. The audit passes when recursion is disabled or the global allow-query-cache list does not contain any. 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).

檢查方式

稽核方法: Shell 指令

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 ' ')
if printf '%s\n' "$opts" | grep -Eq '[{; ]recursion no;'; then echo compliant; exit 0; fi
aq=$(printf '%s\n' "$opts" | grep -Eo 'allow-query-cache \{[^}]*\}') || { echo 'no global allow-query-cache option'; exit 1; }
printf '%s\n' "$aq" | grep -Eq '[{ ]"?any"?;' && { echo 'allow-query-cache contains any'; exit 1; }
echo compliant

預期輸出: compliant

修補方式

修補方法: 操作指南或基礎設施修補檔

Authoritative Only Name Server: For an authoritative name, insert the following either into the global options or into every zone section. allow-query-cache { localhost; }; Caching Only Name Server: Use the previously defined an ACL named trusted_clients which will identify the networks which are expected to use the DNS caching server, and will be allowed to send DNS cache queries. allow-query-cache { localhost; trusted_clients };

屬性

作業系統: 不限
標籤: binddnsaccess-control
參考資料: CIS ISC BIND DNS Server 9.11 Benchmark v1.0.0 - 3.4 Restrict Queries of the Cache

檢查此主機

請在您有權稽核的機器上執行此指令。掃描為唯讀操作。

shell

tmaegis scan --target bind