The Cisco ASA remote access VPN server must be configured to use SHA-2 or greater for hashing to protect the integrity of IPsec remote access sessions.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
|---|---|---|---|---|
| V-239978 | CASA-VN-000630 | SV-239978r769254_rule | Medium |
| Description |
|---|
| Without strong cryptographic integrity protections, information can be altered by unauthorized users without detection. SHA-1 is considered a compromised hashing standard and is being phased out of use by industry and Government standards. DoD systems must not be configured to use SHA-1 for integrity of remote access sessions. The remote access VPN provides access to DoD non-public information systems by an authorized user (or an information system) communicating through an external, non-organization-controlled network. |
| STIG | Date |
|---|---|
| Cisco ASA VPN Security Technical Implementation Guide | 2021-08-16 |
Details
| Check Text ( C-43211r666338_chk ) |
|---|
| Verify the ASA SHA-2 or greater for hashing to protect the integrity of IPsec remote access sessions as shown in the example below. Step 1: Verify that SHA-2 or greater is used for IKE Phase 1 as shown in the example below. crypto ikev2 policy 1 … … … integrity sha256 Step 2: Verify that SHA-2 or greater is used for the IPsec Security Association. crypto ipsec ikev2 ipsec-proposal IPSEC_TRANS protocol esp integrity sha-256 If the ASA does not use SHA-2 or greater for hashing to protect the integrity of IPsec remote access sessions, this is a finding. |
| Fix Text (F-43170r666339_fix) |
|---|
| Configure the ASA to use SHA-2 or greater for hashing to protect the integrity of IPsec remote access sessions as shown in the example below. ASA1(config)# crypto ikev2 policy 1 ASA1(config-ikev2-policy)# integrity sha256 ASA1(config-ikev2-policy)# exit ASA1(config)# crypto ipsec ikev2 ipsec-proposal IPSEC_TRANS ASA1(config-ipsec-proposal)# protocol esp integrity sha-256 ASA1(config-ikev2-policy)# end |