How severe is CVE-2009-2421?

CVE-2009-2421 has a CVSS 2.0 base score of 5.0, rated medium severity.

Is CVE-2009-2421 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2009-2421?

CVE-2009-2421 primarily affects Apple Safari. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2009-2421?

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

When was CVE-2009-2421 published?

CVE-2009-2421 was published on 2009-07-09 and last updated on 2026-06-16.

CVE-2009-2421

CVE-2009-2421 is a medium-severity vulnerability in Apple Safari with a CVSS 2.0 base score of 5.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Severity: Medium (CVSS 2.0 base score 5.0)
EPSS exploit prediction: 3% (83rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Apple Safari
Published: 2009-07-09
Last modified: 2026-06-16

Description

The CFCharacterSetInitInlineBuffer method in CoreFoundation.dll in Apple Safari 3.2.3 allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) or possibly execute arbitrary code via a "high-bit character" in a URL fragment for an unspecified protocol.

Frequently asked questions

What is CVE-2009-2421?: The CFCharacterSetInitInlineBuffer method in CoreFoundation.dll in Apple Safari 3.2.3 allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) or possibly execute arbitrary code via a "high-bit character" in a URL fragment for an unspecified protocol.
How severe is CVE-2009-2421?: CVE-2009-2421 has a CVSS 2.0 base score of 5.0, rated medium severity.
Is CVE-2009-2421 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-2421?: CVE-2009-2421 primarily affects Apple Safari. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2009-2421?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2009-2421 published?: CVE-2009-2421 was published on 2009-07-09 and last updated on 2026-06-16.

References

Affected products (2)

cpe:2.3:a:apple:safari:3.2.3:-:mac:*:*:*:*:*
cpe:2.3:a:apple:safari:3.2.3:-:windows:*:*:*:*:*

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