WordPress Plugin “Ad Inserter” Vulnerable to Code Execution

Ad Inserter, a plugin for managing and inserting online advertisements, contains a critical vulnerability that could allow authenticated actors to remotely execute PHP code on associated websites. The flaw is due to the use of “check_admin_referer()” for authorization, which was designed to protect WordPress sites against cross-site request forgery (CSRF) exploits by using nonces - WordPress discourages the use of nonces for authentication or authorization. The vulnerability impacts all WordPress sites with Ad Inserter version 2.4.21 and below installed. The NJCCIC recommends reviewing the vulnerability details in the Bleeping Computer article and updating to Ad Inserter version 2.4.22 as soon as possible.