The Blocksy theme for WordPress is vulnerable to PHP Object Injection leading to Remote Code Execution via the 'blocksy_meta' REST API field and the V200 database migration in versions up to and including 2.1.35. This is due to insufficient input sanitization in the blocksy_sanitize_post_meta_options() function, which only blocks values containing '<' or '>' and does not prevent serialized PHP object strings from being stored in post meta, combined with the SearchReplacer::run_recursively() function unconditionally deserializing all string values via @unserialize() during migration without restricting allowed classes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject a serialized Blocksy\RaiiPattern object into post meta that, when the V200 migration runs on an upgraded site, is deserialized and triggers RaiiPattern::__destruct(), which executes arbitrary PHP callables via call_user_func().

The Blocksy theme for WordPress is vulnerable to Stored Cross-Site Scripting via the `blocksy_meta` metadata fields in all versions up to, and including, 2.1.30 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.

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in creativethemeshq Blocksy blocksy allows Stored XSS.This issue affects Blocksy: from n/a through <= 2.1.6.

Missing Authorization vulnerability in creativethemeshq Blocksy blocksy allows Exploiting Incorrectly Configured Access Control Security Levels.This issue affects Blocksy: from n/a through <= 2.0.97.

Cross-Site Request Forgery (CSRF) vulnerability in creativethemeshq Blocksy blocksy allows Cross Site Request Forgery.This issue affects Blocksy: from n/a through <= 2.0.22.

The Blocksy theme for WordPress is vulnerable to Stored Cross-Site Scripting via the Contact Info Block link parameter in all versions up to, and including, 2.0.77 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 Blocksy theme for WordPress is vulnerable to Reflected Cross-Site Scripting via the custom_url parameter in all versions up to, and including, 2.0.50 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link.

The Blocksy theme for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘has_field_link_rel’ parameter in all versions up to, and including, 2.0.46 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 Blocksy theme for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘tagName’ parameter in versions up to, and including, 2.0.42 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level permissions and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The Blocksy theme for WordPress is vulnerable to Stored Cross-Site Scripting via the className parameter in the About Me block in all versions up to, and including, 2.0.39 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in creativethemeshq Blocksy blocksy.This issue affects Blocksy: from n/a through <= 2.0.33.

Cross-Site Request Forgery (CSRF) vulnerability in creativethemeshq Blocksy blocksy.This issue affects Blocksy: from n/a through <= 2.0.22.

The Blocksy theme for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's blocks in all versions up to, and including, 2.0.26 due to insufficient input sanitization and output escaping on user supplied attributes like 'className' and 'radius'. 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.

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in creativethemeshq Blocksy blocksy.This issue affects Blocksy: from n/a through <= 2.0.19.