WWBN AVideo is an open source video platform. In 29.0 and earlier, AVideo stores category descriptions from user input and later renders category_description as raw HTML in the Gallery view. A user who can create or edit categories can store JavaScript in a category description, which executes when another user views the affected Gallery/category page. This is a stored XSS in the category description field, separate from previously fixed XSS issues in video titles or comments.

Affected: Packagist: WWBN/AVideo

### Summary

AVideo stores category descriptions from user input and later renders `category_description` as raw HTML in the Gallery view. A user who can create or edit categories can store JavaScript in a category description, which executes when another user views the affected Gallery/category page.

This is a stored XSS in the category `description` field, separate from previously fixed XSS issues in video titles or comments.

### Details

Source:

`objects/categoryAddNew.json.php`

```php $objCat->setDescription($_POST['description']);

Storage setter:

objects/category.php

public function setDescription($description) { $this->description = $description; } ``` Sink:

`plugin/Gallery/view/mainAreaCategory.php` ``` <div id="categoryDescription<?php echo $duid; ?>" style="display: none;"><?php echo $videos[0]['category_description']; ?></div> ``` The value is rendered without `htmlspecialchars()`, `htmlentities()`, `HTMLPurifier`, or equivalent output encoding.

### PoC

Prerequisites:

- AVideo current master / v29.0 - User account with permission to create or edit categories - Gallery plugin/view enabled - At least one video assigned to the affected category

Steps:

1. Log in as a user who can create or edit categories. 2. Create or edit a category. 3. Set the category description to: ``` <img src=x onerror=alert(document.domain)> ``` 4. Save the category. 5. Assign at least one video to that category. 6.…