What is the WordPress `is_serialized()` function and what security risk does it address?

Question

WordPress Expert — Medium

What is the WordPress `is_serialized()` function and what security risk does it address?

Accepted Answer

The WordPress `is_serialized()` function checks if a string contains PHP-serialized data. This is crucial because unserializing user-supplied data can open the door to PHP Object Injection attacks. WordPress meta functions handle serialization automatically, so manual unserialization of user data should be avoided.