A security vulnerability exists in the Microsoft ASN.1 Library that could allow code execution on an affected system. The vulnerability is caused by an unchecked buffer in the Microsoft ASN.1 Library, which could result in a buffer overflow.

An attacker who successfully exploited this buffer overflow vulnerability could execute code with system privileges on an affected system. The attacker could then take any action on the system, including installing programs, viewing data, changing data, deleting data, or creating new accounts with full privileges.

Abstract Syntax Notation 1 (ASN.1) is a data standard that is used by many applications and devices in the technology industry for allowing the normalization and understanding of data across various platforms. More information about ASN.1 can be found in Microsoft Knowledge Base Article 252648.

Affected Software:
Microsoft Windows NT® Workstation 4.0 Service Pack 6a
Microsoft Windows NT Server 4.0 Service Pack 6a
Microsoft Windows NT Server 4.0 Terminal Server Edition Service Pack 6
Microsoft Windows 2000 Service Pack 2, Microsoft Windows 2000 Service Pack 3, Microsoft 2000 Windows Service Pack 4
Microsoft Windows XP, Microsoft Windows XP Service Pack 1
Microsoft Windows XP 64-Bit Edition, Microsoft Windows XP 64-Bit Edition Service Pack 1
Microsoft Windows XP 64-Bit Edition Version 2003, Microsoft Windows XP 64-Bit Edition Version 2003 Service Pack 1
Microsoft Windows Server™ 2003
Microsoft Windows Server 2003 64-Bit Edition

View: Microsoft Security Bulletin MS04-007 (includes download locations)

Source: Microsoft Security