Summary of Microsoft’s Security Bulletin Release for October 2009

This month, we released 13 new bulletins which address 33 vulnerabilities in Windows, Internet Explorer and Microsoft Office. Since we published this information in our advance notification (ANS) last Thursday, we have been asked “is this the most bulletins Microsoft has ever released”? The short answer to that question is yes. However, we have, on several occasions, released between 10 and 12 bulletins so this is business as usual. All of our updates go through extensive quality testing and when they reach the bar for broad distribution, we schedule them for release.

As we noted in the ANS last week, two of the updates address open Security Advisories. MS09-050 addresses the SMBv2 issue in Security Advisory 975497 and MS09-053 addresses the IIS issue discussed in Security Advisory 975191.

Another issue being addressed this month that has received some public attention has to do with security certificates used for authentication. The vulnerabilities being addressed by Security Bulletin MS09-056 could allow spoofing if an attacker gains access to the certificate used by the end user for authentication. We are aware that a rogue certificate was distributed in a public forum but we are not aware of any attempts to use this to attack users.

Below is the severity summary and exploitability index for the 13 new bulletins. We also refer to this as the overall risk and impact summary. As you can see, eight of the bulletins have a rating of Critical. Of those eight, six have an exploitability index rating of 1, which means we believe it is highly likely that we will see exploit code in the wild within the first 30 days from the date of release.

To help with deployment planning, we started publishing our guidance (beginning last month) on which bulletins should be considered first for deployment. Obviously one size does not fit all and each customer will need to consider their own unique situations in addition to this guidance. Our approach is to take a combination of the severity, the exploitability index rating, the range of products affected, and potential mitigations to group these in to a priority 1, 2 or 3. Our Security Research & Defense team, who represent some of the best security researchers in the world, play a key role in this every month as well.

Most of this month’s updates require a restart, so please refer to the bulletins when you’re planning your deployment to ensure you’re fully protected. We want to specifically note that MS09-050 requires a restart but will not prompt you to do so if you install the update manually.

As we do every month, Adrian Stone and I provide a high-level overview of this month’s bulletin release in the following video:

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This month we are also re-releasing MS08-069, vulnerability in Microsoft XML Core Services could allow remote code execution (955218) to add detection for Windows 7 and Windows Server 2008 R2. This component does not ship with these platforms but many applications install it in order to use its functionality.

Finally, you may also notice a change in the severity rating since the advance notification for several versions of Windows in the .NET bulletin (MS09-061). We have elevated the severity of these products from Important to Critical. We do not typically make changes after the advance notification goes out but during our ongoing investigation to protect customers, we determined that this was the appropriate rating for these products when certain versions of the .NET Framework are installed on them.

We encourage all customers to join us tomorrow when Adrian and I will go in to detail on each bulletin and, along with a room full of subject matter experts, answer all of your questions live. So if you can, please join us at 11:00 a.m. PDT (UTC -7). You can register for the webcast at this link.

Thanks!

Jerry Bryant

Update – Resource links:

Update (10/13) Changed the number of vulnerabilities addressed to 33 from 34. CVE-2009-2493 was counted in both MS09-055 and MS09-060.

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