SEO ALert <= 1.59 - Admin+ Stored XSS

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. Go to Vanilla Beans » SEO Alert. 2. In “Slack Alert for” » “Slack Channel” add payload: "> 3. Save to get the XSS trigger.