The Internet Authentication Service (IAS) in Microsoft Windows 2000 SP4, XP SP2 and SP3, Server 2003 SP2, Vista Gold and SP1, and Server 2008 Gold does not properly verify the credentials in an MS-CHAP v2 Protected Extensible Authentication Protocol (PEAP) authentication request, which allows remote attackers to access network resources via a malformed request, aka "MS-CHAP Authentication Bypass Vulnerability."
The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.
| Link | Tags |
|---|---|
| https://docs.microsoft.com/en-us/security-updates/securitybulletins/2009/ms09-071 | vendor advisory |
| http://www.us-cert.gov/cas/techalerts/TA09-342A.html | third party advisory us government resource |
| http://www.securitytracker.com/id?1023291 | vdb entry |
| https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6209 | vdb entry signature |