VULNERABILITY INTELLIGENCE
CVE-2009-3677
CVSS score10 HIGH
EPSS probability21.82%
CISA KEVNot currently listed
Published2009-12-09
Last modified2026-06-16
CVSS vectorAV:N/AC:L/Au:N/C:C/I:C/A:C
Description
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."
Weakness classification
- CWE-94: Improper Control of Generation of Code ('Code Injection')