Insert PHP Code Snippet <= 1.3.4 - Authenticated (Admin+) Stored Cross-Site Scripting

The Insert PHP Code Snippet plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the user's name when accessing the insert-php-code-snippet-manage page in all versions up to, and including, 1.3.4 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with administrator-level access, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This only affects multi-site installations and installations where unfiltered_html has been disabled.