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CVE-2009-3677
The Internet Authentication Service (IAS) in Microsoft Windows 2000 SP4, XP SP2 and SP3, Server 2003 SP2, Vista Gold and SP1, and Server…
High10.0EPSS 21.8%
- Published
- Updated
- Reserved
- Assigned by
- microsoft
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."
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 2.0 | High10.0 | AV:N/AC:L/Au:N/C:C/I:C/A:C |
- EPSS (exploitation in 30 days)
- 21.8% · top 2.3% of all CVEs (5 Nov 2026)
Loading the EPSS history…
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 10.0.
Weakness
Affected products
n/a
- affected n/a
References (4)
- MS09-071 (opens in a new tab)vendor-advisoryx_refsource_MSx_transferred
- TA09-342A (opens in a new tab)third-party-advisoryx_refsource_CERTx_transferred
- 1023291 (opens in a new tab)vdb-entryx_refsource_SECTRACKx_transferred
- oval:org.mitre.oval:def:6209 (opens in a new tab)vdb-entrysignaturex_refsource_OVALx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2009-3677)Record last updated .