GenerateBlocks < 2.2.1 - Insecure Direct Object Reference to Authenticated (Contributor+) Sensitive Information Exposure via Dynamic Tag Replacements

Description

The GenerateBlocks plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 2.2.0. This is due to missing object-level authorization checks in the /wp-json/generateblocks/v1/dynamic-tag-replacements REST endpoint. The endpoint only verifies that the user has the edit_posts capability but does not verify the user has permission to access the specific post or its associated data referenced by attacker-controlled id parameters in dynamic tag content. This makes it possible for authenticated attackers, with Contributor-level access and above, to extract sensitive information from arbitrary posts including author email addresses and non-protected post meta values by crafting dynamic tag payloads such as {{post_meta id:<target>|key:<meta_key>}} and {{post_title id:<target>|link:author_email}}.