The Enterprise Voice, Video, and Messaging Endpoint must prohibit client negotiation to TLS 1.1, TLS 1.0, SSL 2.0, or SSL 3.0.

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 SSL gateways), web servers, and web applications. Application protocols such as HTTPS and DNSSEC use TLS as the underlying security protocol and thus are in scope for this requirement. NIST SP 800-52 provides guidance for client negotiation on either DOD-only or public-facing servers.

Verify the Enterprise Voice, Video, and Messaging Endpoint prohibits client negotiation to TLS 1.1, TLS 1.0, SSL 2.0, and SSL 3.0.

If the Enterprise Voice, Video, and Messaging Endpoint does not prohibit client negotiation to TLS 1.1, TLS 1.0, SSL 2.0, and SSL 3.0, this is a finding.

Configure the Enterprise Voice, Video, and Messaging Endpoint to prohibit client negotiation to TLS 1.1, TLS 1.0, SSL 2.0, or SSL 3.0.