CVE-2009-0775

CVE-2009-0775 is a critical-severity vulnerability in Mozilla Firefox with a CVSS 2.0 base score of 10.0. 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-399.

Key facts

• Severity: Critical (CVSS 2.0 base score 10.0)
• EPSS exploit prediction: 5% (91st percentile)
• Actively exploited: Not listed in CISA KEV
• Weakness: CWE-399
• Affected product: Mozilla Firefox
• Published: 2009-03-05
• Last modified: 2026-06-16

Description

Double free vulnerability in Mozilla Firefox before 3.0.7, Thunderbird before 2.0.0.21, and SeaMonkey before 1.1.15 allows remote attackers to execute arbitrary code via "cloned XUL DOM elements which were linked as a parent and child," which are not properly handled during garbage collection.

Frequently asked questions

What is CVE-2009-0775?

Double free vulnerability in Mozilla Firefox before 3.0.7, Thunderbird before 2.0.0.21, and SeaMonkey before 1.1.15 allows remote attackers to execute arbitrary code via "cloned XUL DOM elements which were linked as a parent and child," which are not properly handled during garbage collection.

How severe is CVE-2009-0775?

CVE-2009-0775 has a CVSS 2.0 base score of 10.0, rated critical severity.

Is CVE-2009-0775 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (91st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2009-0775?

CVE-2009-0775 primarily affects Mozilla Firefox. In total, 88 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2009-0775?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2009-0775 published?

CVE-2009-0775 was published on 2009-03-05 and last updated on 2026-06-16.

References

• http://lists.opensuse.org/opensuse-security-announce/2009-03/msg00002.html
• http://secunia.com/advisories/34137
• http://secunia.com/advisories/34140
• http://secunia.com/advisories/34145
• http://secunia.com/advisories/34272
• http://secunia.com/advisories/34324
• http://secunia.com/advisories/34383
• http://secunia.com/advisories/34417
• http://support.avaya.com/elmodocs2/security/ASA-2009-069.htm
• http://support.avaya.com/japple/css/japple?temp.documentID=366362&temp.productID=154235&temp.releaseID=361845&temp.bucketID=126655&PAGE=Document
• http://www.debian.org/security/2009/dsa-1751
• http://www.mandriva.com/security/advisories?name=MDVSA-2009:075
• http://www.mozilla.org/security/announce/2009/mfsa2009-08.html
• http://www.redhat.com/support/errata/RHSA-2009-0258.html
• http://www.redhat.com/support/errata/RHSA-2009-0315.html
• http://www.redhat.com/support/errata/RHSA-2009-0325.html
• http://www.securityfocus.com/bid/33990
• http://www.securitytracker.com/id?1021796
• http://www.vupen.com/english/advisories/2009/0632
• https://bugzilla.mozilla.org/show_bug.cgi?id=474456
• https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A5806
• https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A5816
• https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6207
• https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A7584
• https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A9681
• https://www.redhat.com/archives/fedora-package-announce/2009-March/msg00769.html
• https://www.redhat.com/archives/fedora-package-announce/2009-March/msg00771.html

Affected products (88)

• cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.0:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.0.1:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.0.2:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.0.3:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.0.4:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.0.5:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.0.6:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.0.7:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.0.8:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.5:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.5.0.1:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.5.0.2:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.5.0.3:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.5.0.4:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.5.0.5:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.5.0.6:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.5.0.7:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.5.0.8:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.5.0.9:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.5.0.10:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.5.0.11:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.5.0.12:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:2.0:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:2.0.0.1:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:2.0.0.2:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:2.0.0.3:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:2.0.0.4:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:2.0.0.5:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:2.0.0.6:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:2.0.0.7:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:2.0.0.8:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:2.0.0.9:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:2.0.0.10:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:2.0.0.11:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:2.0.0.12:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:2.0.0.13:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:2.0.0.14:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:2.0.0.15:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:2.0.0.16:*:*:*:*:*:*:*

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Other CWE-399 (Resource Management Errors) vulnerabilities

• CVE-2015-8104 — Critical (CVSS 10.0): The KVM subsystem in the Linux kernel through 4.2.6, and Xen 4.3.x through 4.6.x, allows guest OS users to cause a…
• CVE-2015-0339 — Critical (CVSS 10.0): Adobe Flash Player before 13.0.0.277 and 14.x through 17.x before 17.0.0.134 on Windows and OS X and before…
• CVE-2015-0335 — Critical (CVSS 10.0): Adobe Flash Player before 13.0.0.277 and 14.x through 17.x before 17.0.0.134 on Windows and OS X and before…
• CVE-2015-0333 — Critical (CVSS 10.0): Adobe Flash Player before 13.0.0.277 and 14.x through 17.x before 17.0.0.134 on Windows and OS X and before…
• CVE-2014-4121 — Critical (CVSS 10.0): Microsoft .NET Framework 2.0 SP2, 3.5, 3.5.1, 4, 4.5, 4.5.1, and 4.5.2 does not properly parse internationalized…
• CVE-2014-0560 — Critical (CVSS 10.0): Use-after-free vulnerability in Adobe Reader and Acrobat 10.x before 10.1.12 and 11.x before 11.0.09 on Windows and OS…

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