Mattermost versions 9.8.0, 9.7.x <= 9.7.4, 9.6.x <= 9.6.2 and 9.5.x <= 9.5.5 fail to prevent users from specifying a RemoteId for their posts which allows an attacker to specify both a remoteId and the post ID, resulting in creating a post with a user-defined post ID. This can cause some broken functionality in the channel or thread with user-defined posts
The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Mattermost | Mattermost | 9.5.0 (including) | 9.5.6 (excluding) |
| Mattermost | Mattermost | 9.6.0 (including) | 9.6.3 (excluding) |
| Mattermost | Mattermost | 9.7.0 (including) | 9.7.4 (excluding) |
| Mattermost | Mattermost | 9.8.0 (including) | 9.8.1 (excluding) |
Access control involves the use of several protection mechanisms such as:
When any mechanism is not applied or otherwise fails, attackers can compromise the security of the product by gaining privileges, reading sensitive information, executing commands, evading detection, etc. There are two distinct behaviors that can introduce access control weaknesses: