cis-bind9-v301-2-4

name	cis-bind9-v301-2-4
description	Set root Ownership of BIND Directories (Automated)
category	cis-bind
version	3.0.1
author	cyberstrike-official
tags	["cis","bind","dns","isc-bind","bind9","permissions-ownership"]
cis_id	2.4
cis_benchmark	CIS ISC BIND DNS Server 9.9 Benchmark v3.0.1
tech_stack	["bind","isc-bind","dns","linux"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

CIS 2.4 — Set root Ownership of BIND Directories

Profile Applicability

• Level 1 - Authoritative Name Server
• Level 1 - Caching Only Name Server

Description

All of the directories under which ISC BIND runs should be owned by root. Of course, any files created at run time by BIND will still be owned by named.

Rationale

Restricting ownership of the directories provides defense in depth and will reduce the probability of unauthorized modifications to those resources. If there was a BIND vulnerability that allowed code execution as the named user, then the code would not be able to modify permissions on the BIND directories owned by root.

Impact

Not Applicable

Audit Procedure

Ensure that the variable $BIND_HOME is set to the directory under which BIND runs, typically the directory /var/named/. In the case of a chroot'ed configuration, the daemon will likely run under /var/named/chroot/, however the upper level directory of /var/named/ should still be used as it is specific to the BIND service, and will include the chroot directory. Also, the variable $RUNDIR should be set to the directory which is used to create run-time files such as the pid file and session-key. Perform the following to ensure the directory ownership:

# find $BIND_HOME $RUNDIR type d \! -user root -ls

There should be NO directories listed in the output from the find command.

Remediation

To correct the directory ownership, perform the following:

chown -R root $BIND_HOME $RUNDIR

Default Value

The following directories are owned by named in the default RHEL7 package install:

• /var/named/dynamic
• /var/named/slaves
• /var/named/data
• /run/named

References

Not Applicable

CIS Controls

Controls Version	Control	IG 1	IG 2	IG 3
v6	14.4 - Protect Information with Access Control Lists	Y