Better Comments < 1.5.6 - Admin+ Stored XSS

Description The plugin does not sanitise and escape some of its settings, which could allow high privilege users such as admin to perform Stored Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed (for example in multisite setup)

PoC

1. From the WordPress menu on the left, go to Better Comments menu. 2. Under the “Form” menu, scroll down until “Form Options”. 3. Enable “Add comment policy”, set “Position” attribute to “after comment box (all users)” and set the “Comment policy” to the payload: 4. Click “Save Changes” on the top right. 5. Open a WordPress post and notice the payload being executed.