SQL Server 2014 vulnerabilities reported by Nessus
It looks like Nessus reports these vulnerabilities even when the RC4 is not enabled for any SQL Server endpoint. For SSL 3.0 SQL Server 2014 supports TLS 1.2 as of CU7, while previous versions support TLS 1.0. 

I suppose that the Nessus report has to do with the possibility of algorithm downgrade from TLS to RC4. This page describes how to disable RC4 completely.

However, some of my servers are still reported by Nessus with this vulnerability, even if the RC4 cypher is disabled (default for Windows 2012 R2), so I suppose it might be a false positive on Nessus' end.