Add support for allowed_classes optional parameter to unserialize
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The PHP
unserializefunction can take an optional parameterallowed_classesto restrict the set of allowed classes that can be deserialized (https://www.php.net/manual/en/function.unserialize.php). When an application has a restricted set of allowed classes at an unserialize call site, an exploit can only use gadgets from the set of allowed classes.We extended FUGIO to support the semantics of the
allowed_classesoptional parameter.This was necessary to evaluate our mitigation for deserialization vulnerabilities that automatically determines a correct set of
allowed_classes, and we hope that it can benefit other researchers in the future.