Betheme <= 26.5.1.4 - Authenticated (Subscriber+) PHP Object Injection

The Betheme theme for WordPress is vulnerable to PHP Object Injection in versions up to, and including, 26.5.1.4 via deserialization of untrusted input supplied via the import, mfn-items-import-page, and mfn-items-import parameters passed through the mfn_builder_import, mfn_builder_import_page, importdata, importsinglepage, and importfromclipboard functions. This makes it possible for authenticated attackers, with subscriber level permissions and above to inject a PHP Object. The additional presence of a POP chain would make it possible for attackers to execute code, retrieve sensitive data, delete files, etc..