While most people know that when they speak to an attorney there is a privilege that attaches to anything said to their attorney. That means that the client can tell their attorney almost anything and the attorney may not divulge it to anyone without the privilege being waived by the client. Therefore, if the client does not want whatever he/she said to their attorney repeated, all they need do is refuse to waive their privilege and the attorney is not able to repeat it to anyone.
However, in order to bring any communication within the rule of law, the statement must be made within the context of "professional employment" or it is not considered privileged. For instance, if an attorney and his 3 friends are playing golf and one of them confesses to committing a crime while they're golfing, that is not a privileged communication and it could be repeated without recourse by the attorney. In fact, the attorney could be forced to disclose it under the appropriate circumstances, like being Subpoenaed before a Grand Jury.