AOS must use Transport Layer Security (TLS) 1.2, at a minimum, to protect the confidentiality of sensitive data during electronic dissemination using remote access.

Using older unauthorized versions or incorrectly configuring protocol negotiation makes the gateway vulnerable to known and unknown attacks that exploit vulnerabilities in this protocol. This requirement applies to TLS gateways (also known as Secure Sockets Layer [SSL] gateways). Application protocols such as Hypertext Transfer Protocol Secure (HTTPS), Secure File Transfer Protocol (SFTP), and others use TLS as the underlying security protocol and thus are in scope for this requirement. National Institute of Standards and Technology (NIST) Special Publication 800-52 provides guidance for client negotiation on either DOD-only or public-facing servers. Satisfies: SRG-NET-000062, SRG-NET-000530

Verify the AOS configuration with the following command: show web-server profile If "tlsv1.2" is not returned for "SSL/TLS Protocol Config", this is a finding.

Configure AOS with the following commands: configure terminal web-server profile ssl-protocol tlsv1.2 exit write memory