CVE-2009-0356

CVE-2009-0356 is a medium-severity vulnerability in Mozilla Firefox with a CVSS 2.0 base score of 5.1. 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-59.

Key facts

Description

Mozilla Firefox before 3.0.6 and SeaMonkey do not block links to the (1) about:plugins and (2) about:config URIs from .desktop files, which allows user-assisted remote attackers to bypass the Same Origin Policy and execute arbitrary code with chrome privileges via vectors involving the URL field in a Desktop Entry section of a .desktop file, related to representation of about: URIs as jar:file:// URIs. NOTE: this issue exists because of an incomplete fix for CVE-2008-4582.

Frequently asked questions

What is CVE-2009-0356?
Mozilla Firefox before 3.0.6 and SeaMonkey do not block links to the (1) about:plugins and (2) about:config URIs from .desktop files, which allows user-assisted remote attackers to bypass the Same Origin Policy and execute arbitrary code with chrome privileges via vectors involving the URL field in a Desktop Entry section of a .desktop file, related to representation of about: URIs as jar:file:// URIs. NOTE: this issue exists because of an incomplete fix for CVE-2008-4582.
How severe is CVE-2009-0356?
CVE-2009-0356 has a CVSS 2.0 base score of 5.1, rated medium severity.
Is CVE-2009-0356 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (87th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-0356?
CVE-2009-0356 primarily affects Mozilla Firefox. In total, 92 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2009-0356?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2009-0356 published?
CVE-2009-0356 was published on 2009-02-04 and last updated on 2026-06-16.

References

Affected products (92)

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