CVE-2013-3735

CVE-2013-3735 is a high-severity vulnerability in Php with a CVSS 3.x base score of 7.5. 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

Description

The Zend Engine in PHP before 5.4.16 RC1, and 5.5.0 before RC2, does not properly determine whether a parser error occurred, which allows context-dependent attackers to cause a denial of service (memory consumption and application crash) via a crafted function definition, as demonstrated by an attack within a shared web-hosting environment. NOTE: the vendor's http://php.net/security-note.php page says "for critical security situations you should be using OS-level security by running multiple web servers each as their own user id.

Frequently asked questions

What is CVE-2013-3735?
The Zend Engine in PHP before 5.4.16 RC1, and 5.5.0 before RC2, does not properly determine whether a parser error occurred, which allows context-dependent attackers to cause a denial of service (memory consumption and application crash) via a crafted function definition, as demonstrated by an attack within a shared web-hosting environment. NOTE: the vendor's http://php.net/security-note.php page says "for critical security situations you should be using OS-level security by running multiple web servers each as their own user id.
How severe is CVE-2013-3735?
CVE-2013-3735 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2013-3735 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (85th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2013-3735?
CVE-2013-3735 primarily affects Php. In total, 30 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2013-3735?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2013-3735 published?
CVE-2013-3735 was published on 2013-05-31 and last updated on 2026-06-16.

References

Affected products (30)

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Threat intelligence

Threat-intel indicators referencing this CVE: