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BIND DNS

TMA-BIND-9.3

Configure a Logging Syslog Channel

MediumLevel 1Automatedbind

Description

The syslog option of the logging configuration allows specification of the syslog facility to send log events. A syslog channel should be configured with the value of daemon or other appropriate syslog facility. The default and general categories should be included and the severity level should be info or lower. The audit requires a logging channel with a syslog destination. 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).

How it is checked

Audit method: Shell command

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 'channel "?[^ ]+"? \{[^}]*[{; ]syslog( "?[a-z0-9]+"?)?;' && echo compliant || echo 'no logging syslog channel'
Expected output
compliant

How it is fixed

Fix method: Guidance or infrastructure patch

Configure a syslog channel to capture at least the default and general categories of log events. For external authoritative name servers, the category lame-servers may be redirect to null, so that it is not logged. Using lame name servers is common for the domains used for SPAM and may overload the log with information that is not very useful. logging { . . . // Syslog channel default_syslog { syslog daemon; # send to syslog's daemon facility severity info; # only send priority info and higher }; category default { default_syslog; }; category general { default_syslog; }; // Too many lame servers, especially from SPAM category lame-servers { null; };

Properties

Operating systems
Any
Tags
binddnsoperations
Reference
CIS ISC BIND DNS Server 9.11 Benchmark v1.0.0 - 9.3 Configure a Logging Syslog Channel

Check this host

Run this on a machine you are allowed to audit. The scan is read-only.

shell
tmaegis scan --target bind