MS15-027: Vulnerability in NETLOGON could allow spoofing: March 10, 2015

Gjelder: Windows Server 2012 R2 DatacenterWindows Server 2012 R2 StandardWindows Server 2012 R2 Essentials


This security update resolves a privately reported vulnerability in Windows. The vulnerability could allow spoofing if an attacker who is logged on to a domain-joined system runs a specially crafted application that could establish a connection with other domain-joined systems as the impersonated user or system. The attacker must be logged on to a domain-joined system and be able to monitor network traffic.


Microsoft has released security bulletin MS15-027. To learn more about this security bulletin:

How to obtain help and support for this security update

Help installing updates:
Support for Microsoft Update

Security solutions for IT professionals:
TechNet Security Troubleshooting and Support

Help protect your Windows-based computer from viruses and malware:
Virus Solution and Security Center

Local support according to your country:
International Support

More Information

Known issues with this security update

  • After you install this security update, you cannot access data on EMC Isilon clusters.


    SMB/SMB2/SMB3 clients may experience logon failures to an EMC Isilon cluster when they authenticate by using the NTLMSSP (NT LAN Manager Security Support Provider) provider. Data that resides on EMC Isilon clusters is unavailable to SMB/SMB2/SMB3 clients. This results in data unavailable (DU) failures. Authentication failures may also affect clients that try to access data through HTTP-based protocols such as RAN.


    This issue occurs when Microsoft security update MS15-027 is installed on an Active Directory server that authenticates users and services that access an EMC Isilon cluster and when NTLM is used to authenticate these Active Directory domain users and services.

    Note Authentication to an EMC Isilon cluster that uses the Kerberos protocol is not affected by this issue.


    To work around this issue, use the Kerberos protocol to authenticate Active Directory domain users.

    More information

    For the latest status of this issue on EMC Isilon OneFS, see Technical and Security Advisories for Isilon OneFS.

    Products that are affected

    All supported versions of EMC Isilon OneFS. These include the following:
    • EMC Isilon OneFS 7.2.0.x
    • EMC Isilon OneFS 7.1.1.x
    • EMC Isilon OneFS 7.1.0.x
    • EMC Isilon OneFS 7.0.2.x
    • EMC Isilon OneFS 7.0.1.x
    • EMC Isilon OneFS 6.5.5.x
    • EMC Isilon OneFS 6.5.4.x
    • EMC Isilon OneFS 6.5.3.x
    • EMC Isilon OneFS 6.5.2.x
    • EMC Isilon OneFS 6.5.1.x
    • EMC Isilon OneFS 6.5.0.x
The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, about the performance or reliability of these products.

File information

The English (United States) version of this software update installs files that have the attributes that are listed in the following tables. The dates and times for these files are listed in Coordinated Universal Time (UTC). The dates and times for these files on your local computer are displayed in your local time and with your current daylight saving time (DST) bias. Additionally, the dates and times may change when you perform certain operations on the files.