CVE-2016-5771

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 15.5% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2016-08-07 · updated 2026-06-17
Weakness: CWE-416

Description

spl_array.c in the SPL extension in PHP before 5.5.37 and 5.6.x before 5.6.23 improperly interacts with the unserialize implementation and garbage collection, which allows remote attackers to execute arbitrary code or cause a denial of service (use-after-free and application crash) via crafted serialized data.

Affected products

Debian Linux: 8.0
openSUSE Leap: 42.1
Opensuse: 13.2
PHP: before 5.5.37; from 5.6.0 before 5.6.23; from 7.0.0 before 7.0.8 — fixed in 5.5.37, 5.6.23, 7.0.8

How to fix

Upgrade to a fixed version: PHP 5.5.37, 5.6.23, 7.0.8. Check the vendor advisory for mitigations.

References

http://github.com/php/php-src/commit/3f627e580acfdaf0595ae3b115b8bec677f203ee?w=1
http://lists.apple.com/archives/security-announce/2016/Sep/msg00006.html
http://lists.opensuse.org/opensuse-security-announce/2016-07/msg00004.html
http://lists.opensuse.org/opensuse-updates/2016-08/msg00003.html
http://php.net/ChangeLog-5.php
http://rhn.redhat.com/errata/RHSA-2016-2750.html
http://www.debian.org/security/2016/dsa-3618
http://www.openwall.com/lists/oss-security/2016/06/23/4
http://www.securityfocus.com/bid/91401
https://bugs.php.net/bug.php?id=72433
https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05240731
https://support.apple.com/HT207170

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