Cisco IOS Switch NDM STIG Version Comparison

There are 2 differences between versions v3 r3 (Jan. 30, 2025) (the "left" version) and v3 r5 (July 2, 2025) (the "right" version).

Check CISC-ND-001150 was changed between these two versions. Green, underlined text was added, red, struck-out text was removed.

The regular view of the left check and right check may be easier to read.

Title

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

Check Content

Review the Cisco switch configuration to verify that it authenticates NTP sources using cryptographically based authentication as shown in the configuration example below: ntp authentication-key 1 hmac-sha2-256 xxxxxx ntp md5 121B0A151012 7 ntp authenticate ntp trusted-key 1 ntp server x.x.x.x key 1 ntp server y.y.y.y key 1 If the Cisco switch is not configured to authenticate NTP sources using authentication that is cryptographically based, this is a finding.

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.

Fix

Configure the Cisco switch to authenticate NTP sources using authentication that is cryptographically based as shown in the example below: SW2(config)#ntp authenticate SW2(config)#ntp authentication-key 1 md5 hmac-sha2-256 xxxxxx SW2(config)#ntp trusted-key 1 SW2(config)#ntp server x.x.x.x key 1 SW2(config)#ntp server y.y.y.y key 1