The Easy Waveform Player plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the shortcode_easywaveformplayer() function in all versions up to, and including, 1.2.2 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.