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V-239929

CAT II (Medium)

The Cisco ASA must be configured to authenticate Network Time Protocol (NTP) sources using authentication with FIPS-compliant algorithms.

Rule ID

SV-239929r1167249_rule

STIG

Cisco ASA NDM Security Technical Implementation Guide

Version

V2R4

CCIs

CCI-001967

Discussion

If NTP 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 Cisco ASA configuration to verify it authenticates NTP sources using authentication with FIPS-compliant algorithms as shown in the configuration example below:

ntp authenticate
ntp trusted-key 1
ntp authentication-key 1 sha256 xxxxxx
ntp server 10.1.12.2 key 1 prefer
ntp server 10.1.48.10 key 1

Note: For ASAs running on Firepower Chassis hardware, the NTP settings are visible in the FXOS web UI only (not in the ASA CLI or ASDM web UI).

If the Cisco ASA is not configured to authenticate NTP sources using authentication with FIPS-compliant algorithms, this is a finding.

Fix Text

Configure the Cisco ASA to authenticate NTP sources using authentication with FIPS-compliant algorithms as shown in the example below:

ASA(config)# ntp authenticate 
ASA(config)# ntp trusted-key 1
ASA(config)# ntp authentication-key 1 sha256 xxxxxx
ASA(config)# ntp server 10.1.12.2 key 1 prefer
ASA(config)# ntp server 10.1.48.10 key 1
ASA(config)# end