ElementsKit Lite < 3.10.01 - Subsite Administrator+ PHP Code Injection via Custom Widget Builder (Multisite)

Description

The plugin does not prevent a custom-widget definition saved by a user with administrative capabilities from being written verbatim into a generated PHP file that the plugin subsequently executes, allowing arbitrary PHP code to run on the server; on a multisite network this lets a non-super subsite Administrator, who is otherwise denied code/file editing, reach host-level code execution beyond the privileges the network grants them.