ClipBucket Missing Authorization Vulnerability Allows Unauthorized Collection Item Modification

A vulnerability in ClipBucket version 5.5.3 #58 and prior allows authenticated users to improperly modify collection items belonging to other users. This issue arises from inadequate authorization checks when adding items to collections and a flawed ownership verification process when deleting items. As a result, users can insert or remove items from collections they do not own, violating content integrity and collection access policies.

Impact

Exploitation of this vulnerability allows users to arbitrarily add or remove items from other users' collections, disregarding established collection management rules.

Reproduction

To reproduce this vulnerability, log in as a normal user and create a collection with 'Public Upload' set to disallow others from adding items. Afterward, use the 'manage_collections.php' page to delete items from this collection, demonstrating the ability to bypass ownership checks.

Remediation

Users can upgrade to ClipBucket version 5.5.3 #59 or later, where this vulnerability has been addressed.