How severe is CVE-2009-2511?

CVE-2009-2511 has a CVSS 2.0 base score of 7.5, rated high severity.

Is CVE-2009-2511 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 13% (96th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2009-2511?

CVE-2009-2511 primarily affects Microsoft Windows 2000. In total, 17 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2009-2511?

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-2009-2511 published?

CVE-2009-2511 was published on 2009-10-14 and last updated on 2026-06-16.

CVE-2009-2511

CVE-2009-2511 is a high-severity vulnerability in Microsoft Windows 2000 with a CVSS 2.0 base score of 7.5. Its EPSS exploit-prediction score of 13% places it in the 96th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-189.

Key facts

Severity: High (CVSS 2.0 base score 7.5)
EPSS exploit prediction: 13% (96th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-189
Affected product: Microsoft Windows 2000
Published: 2009-10-14
Last modified: 2026-06-16

Description

Integer overflow in the CryptoAPI component in Microsoft Windows 2000 SP4, Windows XP SP2 and SP3, Windows Server 2003 SP2, Windows Vista Gold, SP1, and SP2, Windows Server 2008 Gold, SP2, and R2, and Windows 7 allows man-in-the-middle attackers to spoof arbitrary SSL servers and other entities via an X.509 certificate that has a malformed ASN.1 Object Identifier (OID) and was issued by a legitimate Certification Authority, aka "Integer Overflow in X.509 Object Identifiers Vulnerability."

Frequently asked questions

What is CVE-2009-2511?: Integer overflow in the CryptoAPI component in Microsoft Windows 2000 SP4, Windows XP SP2 and SP3, Windows Server 2003 SP2, Windows Vista Gold, SP1, and SP2, Windows Server 2008 Gold, SP2, and R2, and Windows 7 allows man-in-the-middle attackers to spoof arbitrary SSL servers and other entities via an X.509 certificate that has a malformed ASN.1 Object Identifier (OID) and was issued by a legitimate Certification Authority, aka "Integer Overflow in X.509 Object Identifiers Vulnerability."
How severe is CVE-2009-2511?: CVE-2009-2511 has a CVSS 2.0 base score of 7.5, rated high severity.
Is CVE-2009-2511 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 13% (96th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-2511?: CVE-2009-2511 primarily affects Microsoft Windows 2000. In total, 17 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2009-2511?: 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-2009-2511 published?: CVE-2009-2511 was published on 2009-10-14 and last updated on 2026-06-16.

References

Affected products (17)

cpe:2.3:o:microsoft:windows_2000:*:sp4:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_7:-:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2003:*:sp2:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2008:*:*:itanium:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2008:*:*:x32:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2008:*:*:x64:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2008:*:r2:itanium:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2008:*:r2:x64:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2008:*:sp2:itanium:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2008:*:sp2:x32:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2008:*:sp2:x64:*:*:*:*:*
cpe:2.3:o:microsoft:windows_vista:*:*:x64:*:*:*:*:*
cpe:2.3:o:microsoft:windows_vista:*:sp1:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_vista:*:sp2:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_xp:*:sp2:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_xp:*:sp2:professional_x64:*:*:*:*:*
cpe:2.3:o:microsoft:windows_xp:*:sp3:*:*:*:*:*:*

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