The Burst Statistics – Privacy-Friendly Analytics for WordPress plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the burst_total_pageviews_count custom meta field in all versions up to, and including, 1.5.6.1 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. Note that this exploit only functions if the victim has the Show Toolbar when viewing site option enabled in their profile.