The /etc/hosts file must not have an extended ACL.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-22326	GEN001369	SV-37324r1_rule	ECLP-1	Medium

Description
The /etc/hosts file (or equivalent) configures local host name to IP address mappings that typically take precedence over DNS resolution. If this file is maliciously modified, it could cause the failure or compromise of security functions requiring name resolution, which may include time synchronization, centralized authentication, and remote system logging.

STIG	Date
Red Hat Enterprise Linux 5 Security Technical Implementation Guide	2017-03-01

Details

Check Text ( C-36016r1_chk )
Verify /etc/hosts has no extended ACL. # ls -l /etc/hosts If the permissions include a '+', the file has an extended ACL. If the file has an extended ACL and it has not been documented with the IAO, this is a finding.

Fix Text (F-23600r1_fix)
Remove the extended ACL from the file. # setfacl --remove-all /etc/hosts