CVE-2009-4028

CVE-2009-4028 is a medium-severity vulnerability in Mysql 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-20.

Key facts

• Severity: Medium (CVSS 2.0 base score 6.8)
• EPSS exploit prediction: 2% (75th percentile)
• Actively exploited: Not listed in CISA KEV
• Weakness: CWE-20
• Affected product: Mysql
• Published: 2009-11-30
• Last modified: 2026-06-16

Description

The vio_verify_callback function in viosslfactories.c in MySQL 5.0.x before 5.0.88 and 5.1.x before 5.1.41, when OpenSSL is used, accepts a value of zero for the depth of X.509 certificates, which allows man-in-the-middle attackers to spoof arbitrary SSL-based MySQL servers via a crafted certificate, as demonstrated by a certificate presented by a server linked against the yaSSL library.

Frequently asked questions

What is CVE-2009-4028?

The vio_verify_callback function in viosslfactories.c in MySQL 5.0.x before 5.0.88 and 5.1.x before 5.1.41, when OpenSSL is used, accepts a value of zero for the depth of X.509 certificates, which allows man-in-the-middle attackers to spoof arbitrary SSL-based MySQL servers via a crafted certificate, as demonstrated by a certificate presented by a server linked against the yaSSL library.

How severe is CVE-2009-4028?

CVE-2009-4028 has a CVSS 2.0 base score of 6.8, rated medium severity.

Is CVE-2009-4028 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (75th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2009-4028?

CVE-2009-4028 primarily affects Mysql. In total, 104 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2009-4028?

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

When was CVE-2009-4028 published?

CVE-2009-4028 was published on 2009-11-30 and last updated on 2026-06-16.

References

• http://bugs.mysql.com/47320
• http://dev.mysql.com/doc/refman/5.0/en/news-5-0-88.html
• http://dev.mysql.com/doc/refman/5.1/en/news-5-1-41.html
• http://lists.mysql.com/commits/87446
• http://lists.opensuse.org/opensuse-security-announce/2010-05/msg00001.html
• http://marc.info/?l=oss-security&m=125881733826437&w=2
• http://www.openwall.com/lists/oss-security/2009/11/19/3
• http://www.openwall.com/lists/oss-security/2009/11/23/16
• http://www.redhat.com/support/errata/RHSA-2010-0109.html
• http://www.vupen.com/english/advisories/2010/1107
• https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A10940
• https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A8510

Affected products (104)

• cpe:2.3:a:mysql:mysql:*:*:*:*:*:*:*:*
• cpe:2.3:a:mysql:mysql:5.0.0:*:*:*:*:*:*:*
• cpe:2.3:a:mysql:mysql:5.0.1:*:*:*:*:*:*:*
• cpe:2.3:a:mysql:mysql:5.0.2:*:*:*:*:*:*:*
• cpe:2.3:a:mysql:mysql:5.0.3:*:*:*:*:*:*:*
• cpe:2.3:a:mysql:mysql:5.0.4:*:*:*:*:*:*:*
• cpe:2.3:a:mysql:mysql:5.0.5:*:*:*:*:*:*:*
• cpe:2.3:a:mysql:mysql:5.0.5.0.21:*:*:*:*:*:*:*
• cpe:2.3:a:mysql:mysql:5.0.10:*:*:*:*:*:*:*
• cpe:2.3:a:mysql:mysql:5.0.15:*:*:*:*:*:*:*
• cpe:2.3:a:mysql:mysql:5.0.16:*:*:*:*:*:*:*
• cpe:2.3:a:mysql:mysql:5.0.17:*:*:*:*:*:*:*
• cpe:2.3:a:mysql:mysql:5.0.20:*:*:*:*:*:*:*
• cpe:2.3:a:mysql:mysql:5.0.22.1.0.1:*:*:*:*:*:*:*
• cpe:2.3:a:mysql:mysql:5.0.24:*:*:*:*:*:*:*
• cpe:2.3:a:mysql:mysql:5.0.30:*:*:*:*:*:*:*
• cpe:2.3:a:mysql:mysql:5.0.36:*:*:*:*:*:*:*
• cpe:2.3:a:mysql:mysql:5.0.44:*:*:*:*:*:*:*
• cpe:2.3:a:mysql:mysql:5.0.54:*:*:*:*:*:*:*
• cpe:2.3:a:mysql:mysql:5.0.56:*:*:*:*:*:*:*
• cpe:2.3:a:mysql:mysql:5.0.60:*:*:*:*:*:*:*
• cpe:2.3:a:mysql:mysql:5.0.66:*:*:*:*:*:*:*
• cpe:2.3:a:mysql:mysql:5.0.82:*:*:*:*:*:*:*
• cpe:2.3:a:mysql:mysql:5.0.84:*:*:*:*:*:*:*
• cpe:2.3:a:mysql:mysql:5.1.5:*:*:*:*:*:*:*
• cpe:2.3:a:mysql:mysql:5.1.23:*:*:*:*:*:*:*
• cpe:2.3:a:mysql:mysql:5.1.31:*:*:*:*:*:*:*
• cpe:2.3:a:mysql:mysql:5.1.32:*:*:*:*:*:*:*
• cpe:2.3:a:mysql:mysql:5.1.34:*:*:*:*:*:*:*
• cpe:2.3:a:mysql:mysql:5.1.37:*:*:*:*:*:*:*
• cpe:2.3:a:oracle:mysql:5.0.0:alpha:*:*:*:*:*:*
• cpe:2.3:a:oracle:mysql:5.0.3:beta:*:*:*:*:*:*
• cpe:2.3:a:oracle:mysql:5.0.6:*:*:*:*:*:*:*
• cpe:2.3:a:oracle:mysql:5.0.7:*:*:*:*:*:*:*
• cpe:2.3:a:oracle:mysql:5.0.8:*:*:*:*:*:*:*
• cpe:2.3:a:oracle:mysql:5.0.11:*:*:*:*:*:*:*
• cpe:2.3:a:oracle:mysql:5.0.12:*:*:*:*:*:*:*
• cpe:2.3:a:oracle:mysql:5.0.13:*:*:*:*:*:*:*
• cpe:2.3:a:oracle:mysql:5.0.14:*:*:*:*:*:*:*
• cpe:2.3:a:oracle:mysql:5.0.18:*:*:*:*:*:*:*

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