eEye Digital Security has discovered some vulnerabilities in Microsoft Windows, which can be exploited by malicious people to compromise a vulnerable system.

The vulnerabilities are caused due to boundary errors in the Microsoft ASN.1 Library ("msasn1.dll") during ASN.1 BER decoding. These can be exploited via various security services (e.g. Kerberos and NTLMv2 authentication) and applications using certificates to cause a buffer overflow by sending malformed ASN.1 data to the service or application.

Successful exploitation may allow execution of arbitrary code on an affected system with SYSTEM privileges.

Solution
Apply update automatically via WindowsUpdate or manually.
Further details available in Customer Area

Provided and/or discovered by
Derek Soeder, eEye Digital Security.

Changelog
Further details available in Customer Area

Original Advisory
MS04-007 - ASN.1 Vulnerability Could Allow Code Execution:
http://www.microsoft.com/technet/security/bulletin/MS04-007.asp

Microsoft Windows XP Embedded Security Bulletin:
http://www.microsoft.com/downloads/details.aspx?familyid=b11ce242-986e-44eb-b0ba-48cbd99494f0&displaylang=en#filelist

Microsoft ASN.1 Library Length Overflow Heap Corruption:
http://www.eeye.com/html/Research/Advisories/AD20040210.html

Microsoft ASN.1 Library Bit String Heap Corruption:
http://www.eeye.com/html/Research/Advisories/AD20040210-2.html

Solar Eclipse:
http://www.phreedom.org/solar/exploits/msasn1-bitstring/

Other references
Further details available in Customer Area

Deep Links
Links available in Customer Area