Mattermost versions 11.0.x <= 11.0.2, 10.12.x <= 10.12.1, 10.11.x <= 10.11.4, 10.5.x <= 10.5.12 fail to to verify that the token used during the code exchange originates from the same authentication flow, which allows an authenticated user to perform account takeover via a specially crafted email address used when switching authentication methods and sending a request to the /users/login/sso/code-exchange endpoint. The vulnerability requires ExperimentalEnableAuthenticationTransfer to be enabled (default: enabled) and RequireEmailVerification to be disabled (default: disabled).
The requirements for the product dictate the use of an established authentication algorithm, but the implementation of the algorithm is incorrect.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Mattermost_server | Mattermost | 10.5.0 (including) | 10.5.13 (excluding) |
| Mattermost_server | Mattermost | 10.11.0 (including) | 10.11.5 (excluding) |
| Mattermost_server | Mattermost | 10.12.0 (including) | 10.12.2 (excluding) |
| Mattermost_server | Mattermost | 11.0.0 (including) | 11.0.3 (excluding) |