Easy Social Feed < 6.5.4 - Authenticated (Contributor+) Stored Cross-Site Scripting via fb_appid

Description

The Easy Social Feed plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘fb_appid' parameter in versions up to, and including, 6.5.3 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.