3v4l.org

run code in 300+ PHP versions simultaneously
<?php class obj implements Serializable { private $data; public function serialize() { } public function unserialize($data) { $this->data = unserialize($data); // $this->data = 1; } } $inner = 'a:0:{}'; $exploit = 'a:2:{i:0;C:3:"obj":' . strlen($inner) . ':{' . $inner . '}i:1;R:3;}'; $data = unserialize($exploit); var_dump(serialize($data));
Output for 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
Deprecated: obj implements the Serializable interface, which is deprecated. Implement __serialize() and __unserialize() instead (or in addition, if support for old PHP versions is necessary) in /in/bT40n on line 2 string(22) "a:2:{i:0;N;i:1;a:0:{}}"
Output for 5.5.0 - 5.5.38, 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30
string(22) "a:2:{i:0;N;i:1;a:0:{}}"

preferences:
267 ms | 403 KiB | 327 Q