Revision Note: V1.2 (July 8, 2014): Advisory revised to announce a Microsoft Update Catalog detection change for the updates requiring installation of the 2868725 prerequisite update. This is a detection change only. Customers who have already successfully updated their systems do not need to take any action.
Summary: Microsoft is announcing the availability of an update for Microsoft .NET Framework that disables RC4 in Transport Layer Security (TLS) through the modification of the system registry. Use of RC4 in TLS could allow an attacker to perform man-in-the-middle attacks and recover plaintext from encrypted sessions.