All plugins by Essentialplugin for WordPress are vulnerable to an injected backdoor in various versions. This is due to the plugin being sold to a malicious threat actor that embedded a backdoor in all of the plugin's they acquired. This makes it possible for the threat actor to maintain a persistent backdoor and inject spam into the affected sites.

The WP Blog and Widgets WordPress plugin before 2.3.1 does not validate and escape some of its shortcode attributes before outputting them back in the page, which could allow users with a role as low as contributor to perform Stored Cross-Site Scripting attacks which could be used against high privilege users such as admins.