CVE-2009-3677 in the critical feed json
The Internet Authentication Service (IAS) in Microsoft Windows 2000 SP4, XP SP2 and SP3, Server 2003 SP2, Vista Gold and SP1, and Server 20…
published 2009-12-09 16 y ago modified 2026-06-16 4 mo ago also EUVD-2009-3652
- cvss
- 10.0
- version 2.0, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 21.8%
- EPSS 21.8% chance of exploitation in 30 days, percentile 97%
- public exploits
- 0
- none known
Summary
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."
Exploit prediction
21.82% chance of exploitation in the next 30 days, higher than 97% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 2.0 | 10.0 | AV:N/AC:L/Au:N/C:C/I:C/A:C |
Classification
References
-
docs.microsoft.com
/en-us/security-updates/securitybulletins/2009/ms09-071
vendor-advisory
-
us-cert.gov
/cas/techalerts/TA09-342A.html
third-party-advisory, us-government-resource
-
securitytracker.com
/id?1023291
vdb-entry
-
oval.cisecurity.org
/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6209
vdb-entry, signature
Sources
- CVE List CVE-2009-3677
- NVD CVE-2009-3677
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.