The Blog2Social: Social Media Auto Post & Scheduler plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the b2s_curation_draft AJAX action in all versions up to, and including, 8.7.4. The curationDraft() function only verifies current_user_can(read) without checking whether the user has edit_post permission for the target post. Combined with the plugin granting UI access and nonce exposure to all roles, this makes it possible for authenticated attackers, with Subscriber-level access and above, to overwrite the title and content of arbitrary posts and pages by supplying a target post ID via the b2s-draft-id parameter.
Weakness
The product does not perform an authorization check when an actor attempts to access a resource or perform an action.
Potential Mitigations
- Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) [REF-229] to enforce the roles at the appropriate boundaries.
- Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
- For example, consider using authorization frameworks such as the JAAS Authorization Framework [REF-233] and the OWASP ESAPI Access Control feature [REF-45].
- For web applications, make sure that the access control mechanism is enforced correctly at the server side on every page. Users should not be able to access any unauthorized functionality or information by simply requesting direct access to that page.
- One way to do this is to ensure that all pages containing sensitive information are not cached, and that all such pages restrict access to requests that are accompanied by an active and authenticated session token associated with a user who has the required permissions to access that page.
Related Attack Patterns
References
- https://plugins.trac.wordpress.org/browser/blog2social/tags/8.7.3/includes/Ajax/Post.php#L159
- https://plugins.trac.wordpress.org/browser/blog2social/tags/8.7.3/includes/B2S/Curation/Save.php#L39
- https://plugins.trac.wordpress.org/browser/blog2social/trunk/includes/Ajax/Post.php?rev=3462464
- https://www.wordfence.com/threat-intel/vulnerabilities/id/930e7fd6-ae0b-465a-aa93-04ef80011d32?source=cve