A guide to exploit mitigations and the July 2011 security bulletin release

Hello all —

Over the years we’ve often talked about exploit mitigations – DEP, ASLR, SEHOP and so forth – as effective tools for improving computer security, reducing risk, preventing attacks, and minimizing operational disruption. Today we’re releasing a user’s guide to the toolbox: “Mitigating Software Vulnerabilities,” a white paper with practical information on choosing and enabling those mitigations. We hope this paper becomes an indispensable reference for developers, IT pros and end users looking for advice and answers concerning exploit mitigations. The paper, which is in PDF format, is available from the Download Center. For more insight, Matt Miller of the Microsoft Security Engineering Center has written about the paper on the SRD blog.

As I previously mentioned in the Advance Notification Blog on Thursday, today we are releasing four security bulletins, one of which is rated as Critical, and three of which are rated Important. These bulletins will increase protection by addressing 22 vulnerabilities in the following Microsoft products. We’ve marked one bulletin, MS11-053, as our highest deployment priority for the month:

  • MS11-053 (Bluetooth Stack). This security bulletin resolves one privately reported vulnerability in the Windows Bluetooth Stack. This bulletin is rated Critical for Windows Vista and Windows 7 platforms. All prior versions of Windows are unaffected.

Despite its high deployment priority, we have assigned MS11-053 an Exploitability Index rating of 2. For more information on that decision, please see the SRD blog. We encourage all customers to apply this bulletin first, before deploying the rest of our July updates as soon as possible. Of note, consumers with Automatic Update enabled on their computers will not need to take any action; the tool ensures that the updates are applied and the systems protected.

The SRD blog also has insight from MSRC Engineering concerning MS11-056, an Important-level bulletin addressing five issues in Windows’ client/server runtime subsystem.

In this video, Jerry Bryant discusses this month’s bulletins in further detail.

Below is our deployment priority guidance to further assist customers in their deployment planning (click for larger view).

Our risk and impact graph shows an aggregate view of this month’s severity and exploitability index (click for larger view).

More information about this month’s security updates can be found on the Microsoft Security Bulletin summary web page.  

Per our usual process, we’ll offer the monthly technical webcast on Wednesday, hosted by Jerry Bryant and Dustin Childs. I invite you to tune in and learn more about the July security bulletins, as well as other announcements made today. The webcast is scheduled for Wednesday, July 13, 2011 at 11 a.m. PDT, and the registration can be found here.

For all the latest information, you can also follow the MSRC team on Twitter at @MSFTSecResponse.

Thank you,

Angela Gunn
Trustworthy Computing.