In PHP before 5.6.31, an invalid free in the WDDX deserialization of boolean parameters could be used by attackers able to inject XML for deserialization to crash the PHP interpreter, related to an invalid free for an empty boolean element in ext/wddx/wddx.c. Upstream bug: https://bugs.php.net/bug.php?id=74145 Upstream patch: https://git.php.net/?p=php-src.git;a=commit;h=2aae60461c2ff7b7fbcdd194c789ac841d0747d7
This issue happens when untrusted input is deserialized. Doing so is documented as being unsafe: http://php.net/manual/en/function.wddx-deserialize.php Do not pass untrusted user input to wddx_deserialize(). Unserialization can result in code being loaded and executed due to object instantiation and autoloading, and a malicious user may be able to exploit this. Use a safe, standard data interchange format such as JSON (via json_decode() and json_encode()) if you need to pass serialized data to the user.
This issue has been addressed in the following products: Red Hat Software Collections for Red Hat Enterprise Linux 6 Red Hat Software Collections for Red Hat Enterprise Linux 6.7 EUS Red Hat Software Collections for Red Hat Enterprise Linux 7 Red Hat Software Collections for Red Hat Enterprise Linux 7.3 EUS Red Hat Software Collections for Red Hat Enterprise Linux 7.4 EUS Red Hat Software Collections for Red Hat Enterprise Linux 7.5 EUS Via RHSA-2018:1296 https://access.redhat.com/errata/RHSA-2018:1296