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V-220502

The Cisco switch must be configured to authenticate Network Time Protocol (NTP) sources using authentication that is cryptographically based.

Finding ID
CISC-ND-001150
Rule ID
SV-220502r604141_rule
Severity
Cat II
CCE
(None)
Group Title
SRG-APP-000395-NDM-000347
CCI
CCI-001967
Target Key
(None)
Documentable
No
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.

Fix Text

Configure the Cisco switch to authenticate NTP sources using authentication that is cryptographically based as shown in the example below: SW1(config)# ntp authenticate SW1(config)# ntp authentication-key 1 md5 xxxxxxxxxxxxx SW1(config)# ntp trusted-key 1 SW1(config)# ntp server 10.1.12.10 key 1 SW1(config)# ntp server 10.1.22.13 key 1 SW1(config)# ntp commit SW1(config)# end

Check Content

Review the Cisco switch configuration to verify that it is compliant with this requirement as shown in the configuration example below: ntp distribute ntp server 10.1.12.10 key 1 ntp server 10.1.22.13 key 1 ntp authenticate ntp authentication-key 1 md5 xxxxxxxxxx 7 ntp trusted-key 1 ntp commit If the Cisco switch is not configured to authenticate NTP sources using authentication that is cryptographically based, this is a finding.