The Cisco switch must be configured to implement replay-resistant authentication mechanisms for network access to privileged accounts.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-220488 | CISC-ND-000530 | SV-220488r1026069_rule | Medium |
| Description |
| A replay attack may enable an unauthorized user to gain access to the application. Authentication sessions between the authenticator and the application validating the user credentials must not be vulnerable to a replay attack. An authentication process resists replay attacks if it is impractical to achieve a successful authentication by recording and replaying a previous authentication message. |
| STIG | Date |
| Cisco NX OS Switch NDM Security Technical Implementation Guide | 2025-05-19 |
Details
| Check Text (C-22203r1026068_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-22192r1015484_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 |