# MA-330.092012: MyCERT Alert - Microsoft Update For Minimum Certificate Key Length

**Date:** 08 Sep 2012  
**Source:** https://www.mycert.org.my/portal/advisory?id=MA-330.092012  
**Advisory ID:** MA-330.092012

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**1.0 Introduction**
Microsoft is announcing the availability of an update to Windows that restricts the use of certificates with RSA keys less than 1024 bits in length. The private keys used in these certificates can be derived and could allow an attacker to duplicate the certificates and use them fraudulently to spoof content, perform phishing attacks, or perform man-in-the-middle attacks. [1]
**2.0 Impact**
The private keys used in certificates with RSA keys that are less than 1024 bits in length can be derived and could allow an attacker to duplicate the certificates and use them fraudulently to spoof content, perform phishing attacks, or perform man-in-the-middle attacks.
**3.0 Affected Products**
Products listed below are vulnerable to these vulnerabilities:
- Windows XP Service Pack 3
- Windows XP Professional x64 Edition Service Pack 2
- Windows Server 2003 Service Pack 2
- Windows Server 2003 x64 Edition Service Pack 2
- Windows Server 2003 with SP2 for Itanium-based Systems
- Windows Vista Service Pack 2
- Windows Vista x64 Edition Service Pack 2
- Windows Server 2008 for 32-bit Systems Service Pack 2
- Windows Server 2008 for x64-based Systems Service Pack 2
- Windows Server 2008 for Itanium-based Systems Service Pack 2
- Windows 7 for 32-bit Systems and Windows 7 for 32-bit Systems Service Pack 1
- Windows 7 for x64-based Systems and Windows 7 for x64-based Systems Service Pack 1
- Windows Server 2008 R2 for x64-based Systems and Windows Server 2008 R2 for x64-based Systems Service Pack 1
- Windows Server 2008 R2 for Itanium-based Systems
- Windows Server 2008 R2 for Itanium-based Systems Service Pack 1
- Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation)
- Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation)
- Windows Server 2008 R2 for x64-based Systems and Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation)
**4.0 Recommendation**
System administrators of Microsoft Windows platforms are recommended to read Microsoft's KB2661254 article a <http://support.microsoft.com/kb/2661254> and perform an extensive test of the update before doing any wide-scale deployment in their environment. The update will be sent to Microsoft Update for the October 2012 patch cycle. System administrators can obtain the update now from Microsoft's Download Center [4].
MyCERT generally advise users to keep themselves updated with the latest security announcements by the vendor.
MyCERT can be reached through the following channels:
E-mail : [[email protected]](/cdn-cgi/l/email-protection#30534952554209090970534952554243555345425944491e5d49) or [[email protected]](/cdn-cgi/l/email-protection#6d00140e081f192d00140e081f1943021f0a430014)
Phone : 1-300-88-2999 (monitored during business hours)
Fax : +603 89453442
Handphone : +60 19 2665850 (24x7 call incident reporting)
SMS : CYBER999 REPORT <EMAIL> <COMPLAINT> to 15888
Business Hours : Mon - Fri 08:30 -17:30 MYT
Web: [https://www.mycert.org.my](https://www.mycert.org.my/)
**5.0 References**
i. <http://technet.microsoft.com/en-us/security/advisory/2661254>
ii. <http://support.microsoft.com/kb/2661254>
iii. <http://www.us-cert.gov/cas/techalerts/TA12-251A.html>
iv. <http://www.microsoft.com/en-us/download/search.aspx?q=kb2661254>