CVE-2009-3677

Windows 2000 vulnerability

CVSS

10.0

EPSS

21.8%

EPSS pct

97th

Exploited

No known

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."

Affected vendor

Microsoft

Affected product

Windows 2000

CVSS vector

AV:N/AC:L/Au:N/C:C/I:C/A:C

Weakness type (CWE)

CWE-94 — Code Injection
CWE-255

Published

2009-12-09

Risk analysis

Based on its CVSS vector, this vulnerability is exploitable over the network, low attack complexity, requiring no authentication. Successful exploitation leads to complete impact to confidentiality, complete impact to integrity, complete impact to availability.

Its EPSS score of 21.8% reflects a moderate probability of exploitation activity in the wild over the next 30 days, placing it above 97% of all scored CVEs.

Check your external exposure to CVE-2009-3677

Confirm whether Microsoft Windows 2000 is running on any internet-facing host or subdomain.
Match discovered service fingerprints against the version affected by CVE-2009-3677.
Prioritise remediation if the asset is public, business-critical, or near authentication/payment flows.

How ThreatPort helps with CVE-2009-3677

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