Title

The TLS VPN Gateway that supports Government-only services must prohibit client negotiation to TLS 1.1, TLS 1.0, SSL 2.0, or SSL 3.0. (Cat II 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 TLS VPN Gateway that supports Government-only services prohibits client negotiation to TLS 1.1, TLS 1.0, SSL 2.0, or SSL 3.0. If the TLS VPN Gateway that supports Government-only services does not prohibit client negotiation to TLS 1.1, TLS 1.0, SSL 2.0, or SSL 3.0, this is a finding.

Fix Text

Configure the TLS VPN Gateway that supports Government-only services to prohibit client negotiation to TLS 1.1, TLS 1.0, SSL 2.0, or SSL 3.0.

Additional Identifiers

Rule ID: SV-207258r608988_rule

Vulnerability ID: V-207258

Group Title: SRG-NET-000530

Expert Comments

CCIs tied to check.

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