The Ad Inserter – Ad Manager & AdSense Ads plugin for WordPress is vulnerable to Insecure Direct Object Reference in versions up to and including 2.8.16 via the data attribute of the [adinserter] shortcode. This is due to the replace_ai_tags() function processing a {reusable-block-N} tag pattern that calls get_post_field(post_content, N) without verifying the requesting users capability with current_user_can(read_post), without restricting the post type to wp_block, and without checking the post status. This makes it possible for authenticated attackers, with Contributor-level access and above, to read the full content of arbitrary posts including Private, Draft, Pending, Trashed, and password-protected posts owned by other users, by placing the shortcode in a post they own and previewing it.
Weakness
The system’s authorization functionality does not prevent one user from gaining access to another user’s data or record by modifying the key value identifying the data.
Extended Description
Retrieval of a user record occurs in the system based on some key value that is under user control. The key would typically identify a user-related record stored in the system and would be used to lookup that record for presentation to the user. It is likely that an attacker would have to be an authenticated user in the system. However, the authorization process would not properly check the data access operation to ensure that the authenticated user performing the operation has sufficient entitlements to perform the requested data access, hence bypassing any other authorization checks present in the system. For example, attackers can look at places where user specific data is retrieved (e.g. search screens) and determine whether the key for the item being looked up is controllable externally. The key may be a hidden field in the HTML form field, might be passed as a URL parameter or as an unencrypted cookie variable, then in each of these cases it will be possible to tamper with the key value. One manifestation of this weakness is when a system uses sequential or otherwise easily-guessable session IDs that would allow one user to easily switch to another user’s session and read/modify their data.
Potential Mitigations
References
- https://plugins.trac.wordpress.org/browser/ad-inserter/tags/2.8.13/ad-inserter.php#L10569
- https://plugins.trac.wordpress.org/browser/ad-inserter/tags/2.8.13/ad-inserter.php#L10818
- https://plugins.trac.wordpress.org/browser/ad-inserter/tags/2.8.13/ad-inserter.php#L13083
- https://plugins.trac.wordpress.org/browser/ad-inserter/tags/2.8.13/ad-inserter.php#L2101
- https://plugins.trac.wordpress.org/browser/ad-inserter/tags/2.8.16/ad-inserter.php#L10569
- https://plugins.trac.wordpress.org/browser/ad-inserter/tags/2.8.16/ad-inserter.php#L10818
- https://plugins.trac.wordpress.org/browser/ad-inserter/tags/2.8.16/ad-inserter.php#L13083
- https://plugins.trac.wordpress.org/browser/ad-inserter/tags/2.8.16/ad-inserter.php#L2101
- https://plugins.trac.wordpress.org/changeset?sfp_email=\u0026sfph_mail=\u0026reponame=\u0026old=3591792%40ad-inserter\u0026new=3591792%40ad-inserter\u0026sfp_email=\u0026sfph_mail=
- https://www.wordfence.com/threat-intel/vulnerabilities/id/20f0e9ae-786b-4ba8-a6d5-92bf31ebc2c7?source=cve