2960358 - Update for Disabling RC4 in .NET TLS - Version: 2.0

Posted on Tuesday October 13, 2015

Revision Note: V2.0 (October 13, 2015): Advisory revised to broaden the affected software list to include Windows 10 systems that are running .NET Framework 3.5 applications and systems with .NET Framework 4.6 installed that are running .NET Framework 4.5/4.5.1/4.5.2 applications, and to provide customers running these configurations with steps for manually disabling RC4 in TLS. See the Affected Software and Suggested Actions sections of this advisory for more information.
Summary: On May 13, 2014, Microsoft announced 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. Read the bulletin here.