How severe is CVE-2009-0642?

CVE-2009-0642 has a CVSS 2.0 base score of 6.8, rated medium severity.

Is CVE-2009-0642 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (84th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2009-0642?

CVE-2009-0642 primarily affects Ruby-lang Ruby. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2009-0642?

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

When was CVE-2009-0642 published?

CVE-2009-0642 was published on 2009-02-20 and last updated on 2026-06-16.

CVE-2009-0642

CVE-2009-0642 is a medium-severity vulnerability in Ruby-lang Ruby with a CVSS 2.0 base score of 6.8. 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-287.

Key facts

Severity: Medium (CVSS 2.0 base score 6.8)
EPSS exploit prediction: 3% (84th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-287
Affected product: Ruby-lang Ruby
Published: 2009-02-20
Last modified: 2026-06-16

Description

ext/openssl/ossl_ocsp.c in Ruby 1.8 and 1.9 does not properly check the return value from the OCSP_basic_verify function, which might allow remote attackers to successfully present an invalid X.509 certificate, possibly involving a revoked certificate.

Frequently asked questions

What is CVE-2009-0642?: ext/openssl/ossl_ocsp.c in Ruby 1.8 and 1.9 does not properly check the return value from the OCSP_basic_verify function, which might allow remote attackers to successfully present an invalid X.509 certificate, possibly involving a revoked certificate.
How severe is CVE-2009-0642?: CVE-2009-0642 has a CVSS 2.0 base score of 6.8, rated medium severity.
Is CVE-2009-0642 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (84th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-0642?: CVE-2009-0642 primarily affects Ruby-lang Ruby. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2009-0642?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2009-0642 published?: CVE-2009-0642 was published on 2009-02-20 and last updated on 2026-06-16.

References

Affected products (2)

cpe:2.3:a:ruby-lang:ruby:1.8:*:*:*:*:*:*:*
cpe:2.3:a:ruby-lang:ruby:1.9:*:*:*:*:*:*:*

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Other CWE-287 (Improper Authentication) vulnerabilities

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