If you're using a Windows phone, versions 7.8 or 8, there is a new security advisory out with respect to weakness in one of the authentication protocols:
There is a recommended security update - not in the form of a patch or download, but rather in a configuration change. Therefore, read through the Suggested Actions if the scenario applies to your or your environment. The suggested action requires the issuing of a certificate to the wireless access point (WAP) so that the phone can validate the WAP.