The Cisco ASA remote access VPN server must be configured to use SHA-2 at 384 bits or greater for hashing to protect the integrity of IPsec remote access sessions.
An XCCDF Rule
Description
<VulnDiscussion>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 nonpublic information systems by an authorized user (or an information system) communicating through an external, non-organization-controlled network.</VulnDiscussion><FalsePositives></FalsePositives><FalseNegatives></FalseNegatives><Documentable>false</Documentable><Mitigations></Mitigations><SeverityOverrideGuidance></SeverityOverrideGuidance><PotentialImpacts></PotentialImpacts><ThirdPartyTools></ThirdPartyTools><MitigationControl></MitigationControl><Responsibility></Responsibility><IAControls></IAControls>
- ID
- SV-239978r916146_rule
- Severity
- Medium
- References
- Updated
Remediation - Manual Procedure
Configure the ASA to use SHA-2 at 384 bits 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 sha384
ASA1(config-ikev2-policy)# exit
ASA1(config)# crypto ipsec ikev2 ipsec-proposal IPSEC_TRANS