Title

The Juniper router must be configured to authenticate NTP sources using authentication that is cryptographically based. (Cat II impact)

Discussion

If Network Time Protocol is not authenticated, an attacker can introduce a rogue NTP server. This rogue server can then be used to send incorrect time information to network devices, which will make log timestamps inaccurate and affect scheduled actions. NTP authentication is used to prevent this tampering by authenticating the time source.

Check Content

Review the router configuration to verify that it is compliant with this requirement as shown in the configuration example below. system { … … … } ntp { authentication-key 1 type md5 value "$8$LMK7NbHkPTQnVwF/"; ## SECRET-DATA authentication-key 2 type md5 value "$8$I3KceWbwgJUH"; ## SECRET-DATA server x.x.x.x key 1 prefer; ## SECRET-DATA server x.x.x.x key 2; ## SECRET-DATA trusted-key [1 2]; } If the router is not configured to authenticate NTP sources using authentication that is cryptographically based, this is a finding.

Fix Text

Configure the router to authenticate NTP sources using authentication that is cryptographically based as shown in the example below. [edit system ntp] set authentication-key 1 type md5 value xxxxxxxxx set authentication-key 2 type md5 value xxxxxxxxx set server x.x.x.x key 1 prefer set server x.x.x.x key 2 set trusted-key [1 2] Note: SHA1 and SHA2-256 are supported with release 18.2.

Additional Identifiers

Rule ID: SV-217339r879768_rule

Vulnerability ID: V-217339

Group Title: SRG-APP-000395-NDM-000347

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.