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.

An unprivileged user could use the functionality of the NS WooCommerce Watermark WordPress plugin through 2.11.3 to load images that hide malware for example from passing malicious domains to hide their trace, by making them pass through the vulnerable domain.