Microsoft April 2010 Patch Tuesday

Published: 2010-04-13
Last Updated: 2010-04-15 13:49:03 UTC
by Johannes Ullrich (Version: 1)
7 comment(s)

Update 2 

Looks like Don's issue relates to old, old versions of software


Don reported the following:

"I had a problem with MS0-020 (KB980232) and had to uninstall it.  --snip--"


 Overview of the April 2010 Microsoft Patches and their status.

# Affected Contra Indications Known Exploits Microsoft rating ISC rating(*)
clients servers
MS10-019 Vulnerabilities in Windows Authenticode Verification
KB 981210 no known exploits. Severity:Critical
Exploitability: 2,2
Critical Critical
MS10-020 Vulnerabilities in SMB Client (Replaces MS10-006 )
SMB Client
KB 980232 vuln public. Severity:Critical
Exploitability: 3,3,2,2,3
Critical Critical
MS10-021 Privilege Elevation Vulnerabilities in Windows Kernel (Replaces MS10-015 )
Windows Kernel
KB 979683 no known exploits. Severity:Important
Exploitability: ?,?,1,1,?,?,?,?
Important Important
MS10-022 Vulnerability in VBScript Engine
KB 981169 Known Exploits!. Severity:Critical
Exploitability: 1
PATCH NOW! Critical
MS10-023 Vulnerability in Microsoft Office Publisher (Replaces MS08-027 MS09-030 )
KB 981160 no known exploits. Severity:Important
Exploitability: 1
Critical Important
MS10-024 DoS Vulnerability in Microsoft Exchange and SMTP Service
Exchange, SMTP Service
KB 981832 vuln public. Severity:Important
Exploitability: 3,?
Moderate Important
MS10-025 Vulnerability in Micorsoft Windows Media Services
Windows Meida Services
KB 980858 no known exploit. Severity:Critical
Exploitability: 1
Moderate Critical
MS10-026 Vulnerability in Microsoft MPEG Layer 3 Codec
MPEG Layer 3 Codec
KB 977816 no known exploit. Severity:Critical
Exploitability: 1
Critical Moderate
MS10-027 Vulnerability in Windows Media Player (Replaces MS07-047 )
Windows Media Player
KB 979402 no known exploit. Severity:Critical
Exploitability: 1
Critical Moderate
MS10-028 Vulnerabilities in Microsoft Visio (Replaces MS09-062 MS09-005 )
Windows Media Player
KB 980094 no known exploit. Severity:Critical
Exploitability: 1,2
Critical Important
MS10-029 ISATAP Spoofing Vulnerability
KB 978338 no known exploit. Severity:Moderate
Exploitability: ?
Moderate Moderate

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



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


7 comment(s)


Shouldn't CVE-2009-0487 be CVE-2010-0487 or something?
There is a known issue for MS10-022 for systems that have had Windows Script Host 5.6 manually installed that rapid installers should consider:;en-us;981349
Can you explain why your Client ratings for MS10-023 and MS10-028 are critical but Microsoft classifies them as Important?

Under the FAQ for MS10-028 it indicates -
Microsoft Office Visio 2002 and later versions have a built-in feature that prompts a user to Open, Save, or Cancel before opening a document. This mitigating factor reduces the remote code execution vulnerability from Critical to Important because the vulnerability requires more than a single user action to complete the exploit.
You indicate that MS10-022 is a replacement for MS10-022. Humm... Endless loop, recursive call...

Which one, if any, does MS10-022 really replaces?
@Matt, @Francois - Fixed, Thanks!
@Chuck. I guess because we disagree with Microsoft on this. We see a lot of document based attacks. And it is remote code execution.

In pentests we sometimes get the fun of playing with client side attacks using PDFs, so far it has successfully worked in every one.

Users will click OK if it gets them what they think they want. So to me saying that the risk is reduced because the user has to open it is relying on the weakest control ever, the user. True it is slightly less risky that a fully automated exploit, but this will be used in targeted attacks.
@Chuck (in addition to Mark's comment): in , Microsoft assigns an exploitability index of 1 to both MS10-023 (Publisher) and MS10-028 (Visio).

According to an exploitability index of 1 is the highest possible.

Some social engineering is required for these attacks, but as can be seen in a recent PDF attack often this is not hard (even with typos), see

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