The Cisco switch must be configured to use FIPS-validated Keyed-Hash Message Authentication Code (HMAC) to protect the integrity of remote maintenance sessions.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-220503 | CISC-ND-001200 | SV-220503r1026073_rule | High |
| Description |
| Unapproved mechanisms used for authentication to the cryptographic module are not verified; therefore, they cannot be relied upon to provide confidentiality or integrity, and DOD data may be compromised. Nonlocal maintenance and diagnostic activities are those activities conducted by individuals communicating through a network, either an external network (e.g., the internet) or an internal network. Currently, HMAC is the only FIPS-approved algorithm for generating and verifying message/data authentication codes in accordance with FIPS 198-1. Products that are FIPS 140-2 validated will have an HMAC that meets specification; however, the option must be configured for use as the only message authentication code used for authentication to cryptographic modules. Separate requirements for configuring applications and protocols used by each application (e.g., SNMPv3, SSHv2, NTP, HTTPS, and other protocols and applications that require server/client authentication) are required to implement this requirement. Where SSH is used, the SSHv2 protocol suite is required because it includes Layer 7 protocols such as SCP and SFTP, which can be used for secure file transfers. |
| STIG | Date |
| Cisco NX OS Switch NDM Security Technical Implementation Guide | 2025-05-19 |
Details
| Check Text (C-22218r1026072_chk) |
| Review the Cisco router configuration to verify it is compliant with this requirement as shown in the example below. SSH Example ssh macs hmac-sha2-256 hmac-sha2-512 NOTE: Using "fips mode enable" to enable all FIPS protocols disables TACACS+ and RADIUS, which is required for authentication server requirements. It is recommended to enable FIPS-validated protocols manually and keep FIPS mode disabled. If the Cisco router is not configured to use FIPS-validated HMAC to protect the integrity of remote maintenance sessions, this is a finding. |
| Fix Text (F-22207r1015490_fix) |
| Configure SSH to use FIPS-validated HMAC for remote maintenance sessions as shown in the following example: SSH Example R1(config)#ssh macs hmac-sha2-256 hmac-sha2-512 |