CVE-2009-0085

CVE-2009-0085 is a high-severity vulnerability in Microsoft Windows 2000 with a CVSS 2.0 base score of 7.1. Its EPSS exploit-prediction score of 15% places it in the 96th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-287.

Key facts

• Severity: High (CVSS 2.0 base score 7.1)
• EPSS exploit prediction: 15% (96th percentile)
• Actively exploited: Not listed in CISA KEV
• Weakness: CWE-287
• Affected product: Microsoft Windows 2000
• Published: 2009-03-10
• Last modified: 2026-06-16

Description

The Secure Channel (aka SChannel) authentication component in Microsoft Windows 2000 SP4, XP SP2 and SP3, Server 2003 SP1 and SP2, Vista Gold and SP1, and Server 2008, when certificate authentication is used, does not properly validate the client's key exchange data in Transport Layer Security (TLS) handshake messages, which allows remote attackers to spoof authentication by crafting a TLS packet based on knowledge of the certificate but not the private key, aka "SChannel Spoofing Vulnerability."

Frequently asked questions

What is CVE-2009-0085?

The Secure Channel (aka SChannel) authentication component in Microsoft Windows 2000 SP4, XP SP2 and SP3, Server 2003 SP1 and SP2, Vista Gold and SP1, and Server 2008, when certificate authentication is used, does not properly validate the client's key exchange data in Transport Layer Security (TLS) handshake messages, which allows remote attackers to spoof authentication by crafting a TLS packet based on knowledge of the certificate but not the private key, aka "SChannel Spoofing Vulnerability."

How severe is CVE-2009-0085?

CVE-2009-0085 has a CVSS 2.0 base score of 7.1, rated high severity.

Is CVE-2009-0085 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 15% (96th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2009-0085?

CVE-2009-0085 primarily affects Microsoft Windows 2000. In total, 15 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2009-0085?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2009-0085 published?

CVE-2009-0085 was published on 2009-03-10 and last updated on 2026-06-16.

References

• http://osvdb.org/52521
• http://secunia.com/advisories/34215
• http://www.securitytracker.com/id?1021828
• http://www.us-cert.gov/cas/techalerts/TA09-069A.html
• http://www.vupen.com/english/advisories/2009/0660
• https://docs.microsoft.com/en-us/security-updates/securitybulletins/2009/ms09-007
• https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6011

Affected products (15)

• cpe:2.3:o:microsoft:windows_2000:*:sp4:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_server_2003:*:*:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_server_2003:*:sp1:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_server_2003:*:sp1:itanium:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_server_2003:*:sp2:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_server_2008:*:*:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_server_2008:*:*:itanium:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_server_2008:*:*:x64:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_vista:*:*:x64:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_vista:*:sp1:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_vista:gold:*:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_xp:*:*:x64:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_xp:*:sp2:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_xp:*:sp2:x64:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_xp:*:sp3:*:*:*:*:*:*

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