Today Microsoft published hotfix MS15-011 and MS15-014 that addressed a potential issues that could allow an man in the middle attack on computer. This vulnerability affected system that could be compromised by a man in the middle or what I like to call a “Coffee Shop Attack”. The summary is that by interfering with the traffic that is being sent to a client a malicious person can force a client to fall back to default weaker security settings. Once this is done it would then be possible to trick a client into running a malicious logon script.
Therefore Microsoft has released two hotfixes to fix this vulnerability:
- MS015-011 – Microsoft has change the fall back behaviour of security setting if it encounters a corrupt Client Side Extension file.
- MS015-014 – Microsoft has enable mutual authentication for Group Policy UNC paths meaning that a client cannot be tricked into access the same path using a different protocol such as WebDAV.
Needless to say that this is an important update to Windows and one that particularly changes the behaviour of Group Policy to mitigate the threat.
For a much more detail explanation of this see:
This update can only be downloaded via Windows Update but you can get more information on the individual patches at: