The DHCP client must not send dynamic DNS updates.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-22549	GEN007850	SV-63409r1_rule		Medium

Description
Dynamic DNS updates transmit unencrypted information about a system including its name and address and should not be used unless needed.

STIG	Date
Oracle Linux 5 Security Technical Implementation Guide	2020-02-25

Details

Check Text ( C-52115r1_chk )
If the "dhclient" package is not installed, this is not applicable. Verify the DHCP client is configured to not send dynamic DNS updates. Procedure: # grep do-forward-updates /etc/dhclient.conf If the file is not present, does not contain this configuration, or has the setting set to "true", this is a finding.

Fix Text (F-54005r1_fix)
Edit or add the "/etc/dhclient.conf" file and add or edit the "do-forward-updates" setting to false. Procedure: # echo "do-forward-updates false;" >> /etc/dhclient.conf