Detections
Analytics
CASA-VN-000640 - The Cisco VPN remote access server must be configured to use AES256 or greater encryption for the Internet Key Exchange (IKE) Phase 1 to protect confidentiality of remote access sessions - IKE Phase 1 to protect confidentiality of remote access sessions.
Information
Without confidentiality protection mechanisms, unauthorized individuals may gain access to sensitive information via a remote access session.Remote access is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, non-organization-controlled network.
AES is the FIPS-validated cipher block cryptographic algorithm approved for use in DOD. For an algorithm implementation to be listed on a FIPS 140-2/140-3 cryptographic module validation certificate as an approved security function, the algorithm implementation must meet all the requirements of FIPS 140-2/140-3 and must successfully complete the cryptographic algorithm validation process. Currently, NIST has approved the following confidentiality modes to be used with approved block ciphers in a series of special publications: ECB, CBC, OFB, CFB, CTR, XTS-AES, FF1, FF3, CCM, GCM, KW, KWP, and TKW.
Solution
Configure the ASA to use AES256 or greater encryption algorithm for IKE Phase 1 as shown in the example below.ASA1(config)# crypto ikev2 policy 1
ASA1(config-ikev2-policy)# encryption aes-256
See Also
https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_Cisco_ASA_Y26M01_STIG.zip
Item Details
Audit Name: DISA STIG Cisco ASA VPN v2r2
Category: ACCESS CONTROL
References: 800-53|AC-17(2), CAT|I, CCI|CCI-000068, Rule-ID|SV-239979r987747_rule, STIG-ID|CASA-VN-000640, Vuln-ID|V-239979
Plugin: Cisco
Control ID: f62b05204b592f522a22952b50f31116aae605054d41c4c8f4b45ca6ff38f49d