The Freemius SDK, as used by hundreds of WordPress plugin and theme developers, was vulnerable to Cross-Site Request Forgery and Information disclosure due to missing capability checks and nonce protection on the _get_debug_log, _get_db_option, and the _set_db_option functions in versions up to, and including 2.4.2. Any WordPress plugin or theme running a version of Freemius less than 2.4.3 is vulnerable.

The Stackable – Page Builder Gutenberg Blocks plugin for WordPress is vulnerable to CSS Injection in all versions up to, and including, 3.13.6. This makes it possible for unauthenticated attackers to embed untrusted style information into comments resulting in a possibility of data exfiltration such as admin nonces with limited impact. These nonces could be used to perform CSRF attacks within a limited time window. The presence of other plugins may make additional nonces available, which may pose a risk in plugins that don't perform capability checks to protect AJAX actions or other actions reachable by lower-privileged users.

The Stackable – Page Builder Gutenberg Blocks plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘data-caption’ parameter in all versions up to, and including, 3.13.1 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The Stackable – Page Builder Gutenberg Blocks plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the Post(v2) block title tag in all versions up to, and including, 3.12.11 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers with contributor-level and above permissions to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.