The Custom Block Builder – Lazy Blocks plugin for WordPress is vulnerable to Remote Code Execution in all versions up to, and including, 4.2.0 via multiple functions in the 'LazyBlocks_Blocks' class. This makes it possible for authenticated attackers, with Contributor-level access and above, to execute code on the server.
https://plugins.trac.wordpress.org/changeset/3454012/
https://plugins.trac.wordpress.org/browser/lazy-blocks/trunk/classes/class-rest.php#L88
https://plugins.trac.wordpress.org/browser/lazy-blocks/trunk/classes/class-blocks.php#L766
https://plugins.trac.wordpress.org/browser/lazy-blocks/trunk/classes/class-blocks.php#L1637