CVE-2009-3677

Microsoft Windows - Authentication Bypass in IAS MS-CHAP v2 PEAP Request Verification

Title source: llm

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."

References (4)

Core 4

Core References

Vendor Advisory vendor-advisory x_refsource_ms

https://docs.microsoft.com/en-us/security-updates/securitybulletins/2009/ms09-071

US Government Resource third-party-advisory x_refsource_cert

http://www.us-cert.gov/cas/techalerts/TA09-342A.html

Third Party Advisory, VDB Entry vdb-entry x_refsource_sectrack

http://www.securitytracker.com/id?1023291

Third Party Advisory, VDB Entry vdb-entry signature x_refsource_oval

https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6209

Scores

EPSS 0.2182

EPSS Percentile 97.3%

Details

CWE

CWE-255 CWE-94

Status published

Products (5)

microsoft/windows_2000

microsoft/windows_server_2003

microsoft/windows_server_2008 (3 CPE variants)

microsoft/windows_vista (3 CPE variants)

microsoft/windows_xp (3 CPE variants)

Published Dec 09, 2009

Tracked Since Feb 18, 2026