CVE-2009-3677
CVSS Score Not Available
66.70%
MEDIUM RiskEPSS (99th percentile)
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."
Published: 12/9/2009
Modified: 4/9/2025
Vulnerability Summary
EPSS Score (Exploitation Probability)
66.70%MEDIUM Exploitation Risk
99th percentile
This vulnerability has a 66.70% probability of being exploited in the next 30 days, ranking higher than 99% of all scored CVEs.