How severe is CVE-2009-0233?

CVE-2009-0233 has a CVSS 2.0 base score of 5.8, rated medium severity.

Is CVE-2009-0233 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 27% (98th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2009-0233?

CVE-2009-0233 primarily affects Microsoft Windows 2000. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2009-0233?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2009-0233 published?

CVE-2009-0233 was published on 2009-03-11 and last updated on 2026-06-16.

CVE-2009-0233

CVE-2009-0233 is a medium-severity vulnerability in Microsoft Windows 2000 with a CVSS 2.0 base score of 5.8. Its EPSS exploit-prediction score of 27% places it in the 98th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-20.

Key facts

Severity: Medium (CVSS 2.0 base score 5.8)
EPSS exploit prediction: 27% (98th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Microsoft Windows 2000
Published: 2009-03-11
Last modified: 2026-06-16

Description

The DNS Resolver Cache Service (aka DNSCache) in Windows DNS Server in Microsoft Windows 2000 SP4, Server 2003 SP1 and SP2, and Server 2008, when dynamic updates are enabled, does not reuse cached DNS responses in all applicable situations, which makes it easier for remote attackers to predict transaction IDs and poison caches by simultaneously sending crafted DNS queries and responses, aka "DNS Server Query Validation Vulnerability."

Frequently asked questions

What is CVE-2009-0233?: The DNS Resolver Cache Service (aka DNSCache) in Windows DNS Server in Microsoft Windows 2000 SP4, Server 2003 SP1 and SP2, and Server 2008, when dynamic updates are enabled, does not reuse cached DNS responses in all applicable situations, which makes it easier for remote attackers to predict transaction IDs and poison caches by simultaneously sending crafted DNS queries and responses, aka "DNS Server Query Validation Vulnerability."
How severe is CVE-2009-0233?: CVE-2009-0233 has a CVSS 2.0 base score of 5.8, rated medium severity.
Is CVE-2009-0233 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 27% (98th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-0233?: CVE-2009-0233 primarily affects Microsoft Windows 2000. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2009-0233?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2009-0233 published?: CVE-2009-0233 was published on 2009-03-11 and last updated on 2026-06-16.

References

Affected products (7)

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:*:*:x64:*:*:*:*:*

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