December 2011 Microsoft Black Tuesday Summary

Published: 2011-12-13
Last Updated: 2011-12-14 02:29:09 UTC
by Johannes Ullrich (Version: 1)
5 comment(s)

Overview of the December 2011 Microsoft patches and their status.

# Affected Contra Indications - KB Known Exploits Microsoft rating(**) ISC rating(*)
clients servers
MS11-087 True Type Font Remote Execution Vulnerability (Replaces MS11-077)
True Type Font Kernel Drivers
KB 2639417 actively exploited. Severity:Critical
Exploitability: 1
PATCH NOW! Critical
MS11-088 Elevation of Privileges in Chinese version of Microsoft Office
Microsoft Office IME (Chinese)
KB 2652016 no known exploits. Severity:Important
Exploitability: 1
Important N/A
MS11-089 Remote Code Execution Vulnerability in Office (for OS X, replaces MS11-072 )
Microsoft Office (Windows and OS X)
KB 2590602 no known exploits. Severity:Important
Exploitability: 1
Critical N/A
MS11-090 Active X Kill Bits (Replaces MS11-027)
KB 2618451 no known exploits. Severity:Critical
Exploitability: 1
Critical Important
MS11-091 Remote Execution in Microsoft Publisher (Replaces MS10-103)
Microsoft Publisher
KB 2607702 vuln. is disclosed. Severity:Important
Exploitability: 1,1,2
Critical N/A
MS11-092 Remote Execution in Windows Media
Windows Media
KB 2648048 no known exploits. Severity:Critical
Exploitability: 1
Critical N/A
MS11-093 OLE RemoteCode Execution Vulnerability
KB 2624667 no known exploits. Severity:Important
Exploitability: 1
Critical N/A
MS11-094 PowerPoint Remote Execution Vulnerability (Replaces MS11-036 MS11-022 MS11-072)
KB 2639142 no known exploits. Severity:Important
Exploitability: 2
Critical N/A
MS11-095 Vulnerability in Active Directory Could Allow Remote Code Execution (Replaces MS11-086)
Active Directory, Active Directory Application Mode, and Lightweight Directory Service
CVE- 2011-3406
KB 2640045 no known exploits. Severity:Important
Exploitability: 1
Important Important
MS11-096 Vulnerability in Microsoft Excel Could Allow Remote Code Execution (Replaces MS11-072)
Excel 2003
KB 2286198 Exploit code likely. Severity:Important
Exploitability: 1
Critical Important
MS11-097 Vulnerability in Windows Client/Server Run-time Subsystem Could Allow Elevation of Privilege
(Replaces MS11-010)
Run-Time Subsystem
KB 2620712 no known exploit. Severity:Important
Exploitability: 1
Important Important
MS11-098 Vulnerability in Windows Kernel Could Allow Elevation of Privilege
(Replaces MS10-047 MS10-021 MS11-068)
Windows Kernel
KB 2633171 no known exploit. Severity:Important
Exploitability: 1
Important Important
MS11-099 Cumulative Security Update for Internet Explorer
Internet Explorer
KB 2618444 no known exploit. Severity:Important
Exploitability: 3,1
Important Important
We will update issues on this page for about a week or so as they evolve.
We appreciate updates
US based customers can call Microsoft for free patch related support on 1-866-PCSAFETY
(*): ISC rating
  • We use 4 levels:
    • PATCH NOW: Typically used where we see immediate danger of exploitation. Typical environments will want to deploy these patches ASAP. Workarounds are typically not accepted by users or are not possible. This rating is often used when typical deployments make it vulnerable and exploits are being used or easy to obtain or make.
    • Critical: Anything that needs little to become "interesting" for the dark side. Best approach is to test and deploy ASAP. Workarounds can give more time to test.
    • Important: Things where more testing and other measures can help.
    • Less Urgent: Typically we expect the impact if left unpatched to be not that big a deal in the short term. Do not forget them however.
  • The difference between the client and server rating is based on how you use the affected machine. We take into account the typical client and server deployment in the usage of the machine and the common measures people typically have in place already. Measures we presume are simple best practices for servers such as not using outlook, MSIE, word etc. to do traditional office or leisure work.
  • The rating is not a risk analysis as such. It is a rating of importance of the vulnerability and the perceived or even predicted threat for affected systems. The rating does not account for the number of affected systems there are. It is for an affected system in a typical worst-case role.
  • Only the organization itself is in a position to do a full risk analysis involving the presence (or lack of) affected systems, the actually implemented measures, the impact on their operation and the value of the assets involved.
  • All patches released by a vendor are important enough to have a close look if you use the affected systems. There is little incentive for vendors to publicize patches that do not have some form of risk to them.

(**): The exploitability rating we show is the worst of them all due to the too large number of ratings Microsoft assigns to some of the patches.



Johannes B. Ullrich, Ph.D.
SANS Technology Institute

5 comment(s)


Johannes, thanks again for the overview!

I found an improvement though: somehow you've partially mixed up MS11-096 (Excel, KB2640241, important) with MS10-046 (Shell, KB2286198, critical).

MS11-096 applies to Excel from Office 2003 SP3 (and probably all older versions). Although a crafted Excel file sent by e-mail or provided on a web site allows for remote code execution (user interaction required), MS11-096 is rated "important" by Microsoft.
You can't really use the Microsoft rating for much, this is why the ISC rating is much better.
The rating from Microsoft is dependent on how important they think the product is. Office 2003 is old, so it can probably never get any more critical exploits. It is important to keep this in mind when reading the MS rating.
Old or small market products (BizTalk, Commerce Server etc) will probably not get critical unless their is an active exploit in the wild. They do not want to scare their mainstream customers.
BTW: Microsoft only says MS11-087 is moderate. This is because they think the likelihood of a user downloading/double-clicking a file/attachment is close to none.
Exploits in the wild, current attack vectors and attack runs means little to MS.
Does anyone think MS11-095 should be rated High, at least for Domain controllers?

Remote code execution on a DC with “Exploit code likely” <- read reliably exploitable. Or is just the fact that some domain credentials are needed and that there may be a firewall somewhere reason to rate it only important? Interested to see what your thoughts are on this.
One tidbit regarding MS11-095 can be found at . Specifically, under Notes they mention, "Not all domain controllers are vulnerable. Attacker can only trigger vulnerability on a DC’s that return a certain sequence of content to an LDAP query." So perhaps that mitigating factor is why they ranked it a moderate. I've been watching the SRD blog in hopes they'll post some interesting explanation of the whole thing that might prove illuminating and edifying. ;)

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