EWWW Image Optimizer <= 8.7.0 - Authenticated (Administrator+) Cross-Site WebP File Deletion or Rename

The EWWW Image Optimizer plugin for WordPress is vulnerable to Arbitrary File Deletion in all versions up to, and including, 8.7.0. This is due to missing upload-directory scope enforcement in the WebP migration file-operation routine, allowing paths outside the current site's uploads folder on multisite. This makes it possible for authenticated attackers, with administrator-level access and above, to rename or delete WebP-derivative image files outside their own site's uploads directory, including files belonging to other sites on a multisite network.

An attacker needs Administrator access first, so the firewall sees the attempt as traffic from a logged-in account: WordSec's web application firewall inspects request payloads before WordPress loads them. Classes like this one can leave something behind, so the staged malware scanner is the second half: it looks for dropped files and modified code rather than for the request that created them. None of that substitutes for the fix: EWWW Image Optimizer 8.8.0 closes this, and updating the plugin is the step that ends it.

• Firewall
• Scanner
• Alerts