JUEX-NM-000490 - The Juniper EX switch must use an an NTP service that is hosted by a trusted source or a DOD-compliant enterprise or local NTP server.

Information

If a trusted time source is not used, 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 which may hide attacks or result in inaccurate forensic analysis.

The recommended solution is that the application or endpoint is configured to point to an enterprise or site-owned time server that is DOD-compliant (instead of directly to an NTP source as implied by the current wording of the requirement). Most products are unable to meet the requirement, but DISA can mitigate the risk by using a trusted time source. So the requirement should state that NTPS is used with USNO NTP as an alternative mitigation for this to be marked as Not a Finding.

More information can be found at:
https://www.cnmoc.usff.navy.mil/Our-Commands/United-States-Naval-Observatory/Precise-Time-Department/Network-Time-Protocol-NTP/DoD-Customer-Servers/

DOD users should not use tick, tock, or ntp2. There are also instructions for obtaining authenticated NTP at the site listed above.

Solution

Configure the network device to authenticate Network Time Protocol sources using FIPS-validated algorithms.

set system ntp authentication-key 1 type sha256
set system ntp authentication-key 1 value 'PSK'
set system ntp authentication-key 2 type sha1
set system ntp authentication-key 2 value 'PSK'
set system ntp server <address 1> key 1
set system ntp server <address 1> prefer
set system ntp server <address 2> key 2
set system ntp trusted-key 1
set system ntp trusted-key 2

If the network device does not support FIPS-validated algorithms, configure NTP authentication using cryptographically based algorithms.
set system ntp authentication-key 3 type md5
set system ntp authentication-key 3 value 'PSK'
set system ntp server <address 3> key 3
set system ntp trusted-key 3

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_Juniper_EX_Switches_Y24M07_STIG.zip

Item Details

Category: IDENTIFICATION AND AUTHENTICATION

References: 800-53|IA-3(1), CAT|III, CCI|CCI-001967, Rule-ID|SV-253926r961506_rule, STIG-ID|JUEX-NM-000490, Vuln-ID|V-253926

Plugin: Juniper

Control ID: ee250945f35de961b5300128bf16677784444b6c9b4b74a626364821851d3dba