Threat Level: green Handler on Duty: Jim Clausing

SANS ISC: April 2011 Microsoft Black Tuesday Summary - SANS Internet Storm Center SANS ISC InfoSec Forums

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April 2011 Microsoft Black Tuesday Summary

Here are the April 2011 Black Tuesday patches.  Enjoy!

Overview of the April 2011 Microsoft Patches and their status.

# Affected Contra Indications Known Exploits Microsoft rating ISC rating(*)
clients servers
MS11-018 Cumulative Security Update for Internet Explorer ( Replaces MS11-003 )
Internet Explorer 6-8
KB 2497640 No Known Exploits. Severity:Critical
Exploitability: 1,1,?,3,1
Critical Critical
MS11-019 Vulnerabilities in SMB Client Could Allow Remote Code Execution ( Replaces MS10-020 )
KB 2511455 No Known Exploits. Severity:Critical
Exploitability: 2,1
Critical Critical
MS11-020 Vulnerability in SMB Server Could Allow Remote Code Execution ( Replaces MS10-012 MS10-054 )
KB 2508429 No Known Exploits. Severity:Critical
Exploitability: 1
Critical Critical
MS11-021 Vulnerabilities in Microsoft Excel Could Allow Remote Code Execution ( Replaces MS10-080 MS10-087 )
Office XP SP3-2010, Office 2004-2011 for Mac, Open XML File Format Converter, Excel Viewer SP2, Office Compatibility Pack for 2007 file formats
KB 2489279 No Known Exploits. Severity:Important
Exploitability: 1,1,1,2,2,2,1,1,1
Important Important
MS11-022 Vulnerabilities in Microsoft PowerPoint Could Allow Remote Code Execution ( Replaces MS09-017 MS10-036 MS10-087 MS10-088 )
KB 2489283 No Known Exploits. Severity:Important
Exploitability: 2,2,1
Important Important
MS11-023 Vulnerabilities in Microsoft Office Could Allow Remote Code Execution ( Replaces MS10-087 )
Office XP - 2007, Office 2004 - 2008 for Mac, Open XML File Format Converter
KB 2489293 POC Available. Severity:Important
Exploitability: 1,2
Important Important
MS11-024 Vulnerability in Windows Fax Cover Page Editor Could Allow Remote Code Execution
Fax Services, Fax Server Role
KB 2527308 POC Available. Severity:Important
Exploitability: 3
Critical Important
MS11-025 Vulnerability in Microsoft Foundation Class (MFC) Library Could Allow Remote Code Execution
Visual Studio .NET 2003 - 2010, Visual C++ 2005 - 2010 Redistributable Package
KB 2500212 No Known Exploits. Severity:Important
Exploitability: 1
Important Important
MS11-026 Vulnerability in MHTML Could Allow Information Disclosure
KB 2503658 ACTIVELY EXPLOITED. Severity:Important
Exploitability: 3
PATCH NOW! Important
MS11-027 Cumulative Security Update of ActiveX Kill Bits ( Replaces MS10-034 )
Windows XP- 7, Server 2003-2008
KB 2508272 POC Available. Severity:Critical
Exploitability: ?,?,?
Critical Critical
MS11-028 Vulnerability in .NET Framework Could Allow Remote Code Execution ( Replaces MS09-061 MS10-060 MS10-077 )
.NET framework (all supported version)
KB 2484015 No Known Exploits. Severity:Critical
Exploitability: 1
Critical Critical
MS11-029 Vulnerability in GDI+ Could Allow Remote Code Execution ( Replaces MS09-062 MS10-087 )
Windows XP-Vista, Windows Server 2003-2008, Office XP
KB 2489979 No Known Exploits. Severity:Critical
Exploitability: 1
Critical Critical
MS11-030 Vulnerability in DNS Resolution Could Allow Remote Code Execution ( Replaces MS08-020 MS08-037 MS08-066 )
Windows XP - 7, Windows Server 2008
KB 2509553 No Known Exploits. Severity:Critical
Exploitability: 2
Critical Critical
MS11-031 Vulnerability in JScript and VBScript Scripting Engines Could Allow Remote Code Execution ( Replaces MS09-045 MS10-022 MS11-009 )
OpenType Compact Font Format (CFF) driver
KB 2514666 No Known Exploits. Severity:Critical
Exploitability: 2
Critical Important
MS11-032 Vulnerability in the OpenType Compact Font Format (CFF) Driver Could Allow Remote Code Execution ( Replaces MS11-007 )
OpenType Compact Font Format (CFF) driver
KB 2507618 No Known Exploits. Severity:Critical
Exploitability: 3
Critical Important
MS11-033 Vulnerability in WordPad Text Converters Could Allow Remote Code Execution ( Replaces MS10-067 )
Microsoft Wordpad
KB 2485663 No Known Exploits. Severity:Important
Exploitability: 1
Important Important
MS11-034 Elevation of Privilege Vulnerabilities in Windows Kernel-Mode Drivers (Replaces MS10-012 )
Kernel Mode Drivers
KB 2506223 No Known Exploits. Severity:Important
Exploitability: 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,1,1,1,3,1,1,1,1
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

Jim Clausing, GIAC GSE #26
jclausing --at-- isc [dot] sans (dot) edu

SANS SEC401 coming to central OH in May, see


399 Posts
ISC Handler
How come for example MS11-019 is listed as no known exploits but checking the security focus link via CVE-2011-0654, there are two PoC available (i.e.
Please refer people to the "Frequently Asked Questions (FAQ) Related to This Security Update" section of MS11-025.

<i><b>I am a third-party application developer and I use Visual C++. How do I update my application?</b>
For developers of applications who statically link the MFC libraries, applying this update is the only action. If you dynamically link MFC within your application, you will need to apply the update and recompile your program.</i>

I suspect that, unless MS is using a different terminology, they mixed up "static" and "dynamic", but the point that developers need to recompile after applying the update is an important one and should be spread to a wider audience.

4 Posts Posts
Watcher60, that was probably an oversight on my part. The Microsoft bulletin didn't suggest the existence of PoC and, frankly, with the huge number of CVEs, I didn't look at all the CVE entries (some of which are often not yet public when we get the bulletins). I'll update the diary entry.

399 Posts Posts
ISC Handler
Update broke my Calendar sidebar app. Before, a white numeral on orange background for today's date. Now, only orange background.

Win 7 64-bit SP1
Might be worth mentioning

Fix to Windows Operating System Loader for unsigned OS component loading - e.g. root kits.
This round of patches have left both ISA 2006 servers unavailable by RDP access after reboot.

1 Posts Posts
@Tony what OS? If 2003 make sure an old dns issue isn't biting you -

34 Posts Posts
You may wanna try
A heads-up for anyone forced by budget constraints to work with slightly(!) out of date software follows: Update KB2467175 (MS11-025: security update for Visual C++ 2005 SP1 Redistributable Package: April 12, 2011) prevented the Information Store service of Exchange 2000 Server (yes, I know...) on Windows 2000 Server (yes, I KNOW...) from starting with Event ID 26 and message "Application popup: store.exe - Entry Point Not Found : The procedure entry point FindActCtxSectionStringW could not be located in the dynamic link library KERNEL32.dll." This caused a further event ID 7024 "The Microsoft Exchange Information Store service terminated with service-specific error 0." to be logged by the Service Control Manager

Uninstalling the update did not fix the problem, even after a reboot. I had to manually restore from backup the dll files replaced by the update and then reboot. Those files are listed in the MS KB here:

The update also caused the AVG 8.5 user interface to fail to start with a similar "FindActCtxSectionStringW could not be located" message.

NB: the problem with the Exchange Store did not come to light straight away but only when the service was stopped for the offline part of the nightly backup. Here's hoping you don't waste 2 hours reinstalling & re-patching Exchange like I did... on the plus side the store itself was intact & started fine once the dll files were restored.

Hope this helps someone!
While one of my colleagues was speaking to Microsoft yesterday they indicated some initial feedback on MS11-028 indicated there may be some concerns with this patch. No specific details but tread carefully and as always, test thoroughly before deploying.
Is anyone else having a problem with their ISA servers after applying patches, like Tony who posted on Wednesday. I applied on one ISA with no trouble but approaching the others with caution.
Was also unable to RDP after applying updates and rebooting certain servers. Rebooted each problem server a second time and RDP started working fine. Very odd, but easily resolved in my case.
@Tony & John Sheats I've run into this problem a few times, it is mainly do to with not being connected as console when doing the reboot. Ms have this to say on the matter:…

@Louisa I've patched a bunch of ISA 2006 and TMG 2010 without any problems

105 Posts Posts
ISC Handler
MS011-022 for PowerPoint has known issues with PowerPoint 2003 - see

"Presentations that contain layouts with a background images may cause an error when opened in PowerPoint 2003. A dialog will notify you that some contents (text, images or objects) have corrupted; the specific content lost will be what is specified in the layout, not the actual slide content itself. Items that were removed will display a blank box or a box containing “cleansed”."

They offer a workaround, but if you have been using a template with background images for "all" your PPT files then you will have to manually recover all these files...

It is tempting to wait for Microsoft to post "more information" and hopefully an updated update.

60 Posts Posts
12 Apr 2011 - "... The second advisory, KB 2506014*, hardens Windows against kernel-mode rootkits. This specifically breaks the hiding mechanism used by the current Alureon/TDL4 rootkit family..."
[MS11-034 - "30 of this month’s 64 vulnerabilities being addressed in this bulletin..."]
Update April 13: Corrected the MS11-028 bulletin severity and affected products. Also moved this bulletin up higher in priority due to this correction.
*Update April 15: Corrected the MS11-032 bulletin exploitability due to a rating error. Also moved MS11-032 higher in priority order.

April 15, 2011 - "... patch specifically breaks the hiding mechanism used by the current Alureon/TDL4 rootkit family. More information can be found in the security bulletin for MS11-034*..."

160 Posts Posts
MS11-028 (KB2449742)
Causes problems on Server 2008 SP2 with Exchange 2010 SP1. After installing, OWA was crashing, free/busy time didn't work and offline address book distribution didn't work.

This also causes event viewer to crash, powershell and exchange management console to crash.

Removal of this update on the CAS server seems to fix the problem. It doesn't appear to affect servers with the mailbox role.

Some people think that this could be only an issue if using Symantec antivirus. We're using SEP 11 RU6a MP3 and have the issue.

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