Title

The Unified Communications Endpoint must prohibit client negotiation to TLS 1.1, TLS 1.0, SSL 2.0, or SSL 3.0. (Cat I impact)

Discussion

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.

Check Content

Verify the Unified Communications Endpoint prohibits client negotiation to TLS 1.1, TLS 1.0, SSL 2.0, and SSL 3.0. If the Unified Communications Endpoint does not prohibit client negotiation to TLS 1.1, TLS 1.0, SSL 2.0, and SSL 3.0, this is a finding.

Fix Text

Configure the Unified Communications Endpoint to prohibit client negotiation to TLS 1.1, TLS 1.0, SSL 2.0, or SSL 3.0.

Additional Identifiers

Rule ID: SRG-NET-000530-VVEP-00101_rule

Vulnerability ID: SRG-NET-000530-VVEP-00101

Group Title: SRG-NET-000530-VVEP-00101

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.