Can Lawyers be held liable for their client lieing?

My past experience with attorneys has always been to provide them proof of allegations I made against my ex husband in regard to violating family court orders. Is this a rule all attorneys follow or just the ones I have dealt with in the past? Would it be ethical for an attorney to just go by what someone tells them is the truth without asking for validation of the facts? By this I mean verifying and submitting to the court the affidavit their client swore to without getting any proof except what their client told them?