High, CVSS 7.7PackagistPublished
Flarum post mentions can be used to read any post on the forum without access control
CVE-2023-22487 · GHSA-22m9-m3ww-53h3
- Affected
- Packagist flarum/mentions < 1.6.3
- Fixed in
- 1.6.3· Vendor fix available
- Issue
- Using the mentions feature provided by the flarum/mentions extension, users can mention any post ID on the forum with the special @"<username"#p<id syntax. The following behavior never changes no matter if the actor should be able to read the mentioned post or not: A URL to the mentioned post is inserted into the actor post HTML, leaking its discussion ID and post number. The mentionsPosts relationship included in the POST /api/posts and PATCH /api/posts/<id JSON responses leaks the full JSON:API payload of all mentioned posts without any access control. This includes the content, date, number and attributes added by other extensions. An attacker only needs the ability to create new posts on the forum to exploit the vulnerability. This works even if new posts require approval. If they have the ability to edit posts, the attack can be performed even more discreetly by using a single post to scan any size of database and hiding the attack post content afterward. Impact The attack…
Recommended action: Upgrade to 1.6.3 or later, then redeploy and verify.A vendor fix does not resolve your finding until you verify it in your own systems.