The Horizon Connection Server must force server cipher preference.

By default, during the initial setup of a Transport Layer Security (TLS) connection to the Horizon Connection Server, the client sends a list of supported cipher suites in order of preference. The Connection Server replies with the cipher suite it will use for communication, chosen from the client list. This is not ideal since the untrusted client is setting the boundaries and conditions for the connection to proceed. The client could potentially specify known weak cipher combinations that would make the communication more susceptible to interception. By adding the "honorClientOrder" setting to the locked.properties file, the Connection Server will reject the client preference and force the client to choose from the server ordered list of preferred ciphers.