Mattermost versions 9.9.x <= 9.9.0, 9.5.x <= 9.5.6, 9.7.x <= 9.7.5 and 9.8.x <= 9.8.1 fail to disallow unsolicited invites to expose access to local channels, when shared channels are enabled, which allows a malicious remote to send an invite with the ID of an existing local channel, and that local channel will then become shared without the consent of the local admin.
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) | 9.5.7 (excluding) |
| Mattermost | Mattermost | 9.7.0 (including) | 9.7.6 (excluding) |
| Mattermost | Mattermost | 9.8.0 (including) | 9.8.2 (excluding) |
| Mattermost | Mattermost | 9.9.0 (including) | 9.9.0 (including) |
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: