CVE-2009-3558

CVE-2009-3558 is a medium-severity vulnerability in Php 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-264.

Key facts

Description

The posix_mkfifo function in ext/posix/posix.c in PHP before 5.2.12 and 5.3.x before 5.3.1 allows context-dependent attackers to bypass open_basedir restrictions, and create FIFO files, via the pathname and mode arguments, as demonstrated by creating a .htaccess file.

Frequently asked questions

What is CVE-2009-3558?
The posix_mkfifo function in ext/posix/posix.c in PHP before 5.2.12 and 5.3.x before 5.3.1 allows context-dependent attackers to bypass open_basedir restrictions, and create FIFO files, via the pathname and mode arguments, as demonstrated by creating a .htaccess file.
How severe is CVE-2009-3558?
CVE-2009-3558 has a CVSS 2.0 base score of 6.8, rated medium severity.
Is CVE-2009-3558 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (79th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-3558?
CVE-2009-3558 primarily affects Php. In total, 61 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2009-3558?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2009-3558 published?
CVE-2009-3558 was published on 2009-11-23 and last updated on 2026-06-16.

References

Affected products (61)

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Threat intelligence

Threat-intel indicators referencing this CVE: