Is CVE-2009-3677 in the CISA KEV catalog?

No. CVE-2009-3677 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2009-3677?

CVE-2009-3677 has a CVSS v2 base score of 10.0 (HIGH).

What is the EPSS score for CVE-2009-3677?

CVE-2009-3677 has an EPSS score of 21.82% (97th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2009-3677

HIGHEPSS 97th pctl

10.0

CVSS v2

NVD

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."

CWE-94Code Injection CWE-255

CVSS v2 Vector

No CVSS vector data available.

Exploit Intelligence

21.82%probability of exploitation in 30 days

97thpercentile

Very high risk: more likely to be exploited than 97% of all known CVEs.

References

Find and fix vulnerabilities across your fleet

TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.

Start free

This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-04-23.