How severe is CVE-2009-3294?

CVE-2009-3294 has a CVSS 2.0 base score of 5.0, rated medium severity.

Is CVE-2009-3294 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-2009-3294?

CVE-2009-3294 affects Php. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2009-3294?

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

When was CVE-2009-3294 published?

CVE-2009-3294 was published on 2009-09-22 and last updated on 2026-06-16.

CVE-2009-3294

CVE-2009-3294 is a medium-severity vulnerability in Php with a CVSS 2.0 base score of 5.0. 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-134.

Key facts

Severity: Medium (CVSS 2.0 base score 5.0)
EPSS exploit prediction: 3% (84th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-134
Affected product: Php
Published: 2009-09-22
Last modified: 2026-06-16

Description

The popen API function in TSRM/tsrm_win32.c in PHP before 5.2.11 and 5.3.x before 5.3.1, when running on certain Windows operating systems, allows context-dependent attackers to cause a denial of service (crash) via a crafted (1) "e" or (2) "er" string in the second argument (aka mode), possibly related to the _fdopen function in the Microsoft C runtime library. NOTE: this might not cross privilege boundaries except in rare cases in which the mode argument is accessible to an attacker outside of an application that uses the popen function.

Frequently asked questions

What is CVE-2009-3294?: The popen API function in TSRM/tsrm_win32.c in PHP before 5.2.11 and 5.3.x before 5.3.1, when running on certain Windows operating systems, allows context-dependent attackers to cause a denial of service (crash) via a crafted (1) "e" or (2) "er" string in the second argument (aka mode), possibly related to the _fdopen function in the Microsoft C runtime library. NOTE: this might not cross privilege boundaries except in rare cases in which the mode argument is accessible to an attacker outside of an application that uses the popen function.
How severe is CVE-2009-3294?: CVE-2009-3294 has a CVSS 2.0 base score of 5.0, rated medium severity.
Is CVE-2009-3294 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-2009-3294?: CVE-2009-3294 affects Php. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2009-3294?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2009-3294 published?: CVE-2009-3294 was published on 2009-09-22 and last updated on 2026-06-16.

References

Affected products (1)

cpe:2.3:a:php:php:*:*:*:*:*:*:*:*

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Threat intelligence

Threat-intel indicators referencing this CVE:

82.199.197.245 (ipv4-addr)
58.221.244.34 (ipv4-addr)
76.133.97.153 (ipv4-addr)
223.82.97.51 (ipv4-addr)
183.6.115.88 (ipv4-addr)
171.100.156.38 (ipv4-addr)
116.232.75.154 (ipv4-addr)