Craft is a content management system (CMS). In versions 4.5.0-RC1 through 4.16.18 and 5.0.0-RC1 through 5.8.22, a Time-of-Check-Time-of-Use (TOCTOU) race condition exists in Craft CMS’s token validation service for tokens that explicitly set a limited usage. The getTokenRoute() method reads a token’s usage count, checks if it’s within limits, then updates the database in separate non-atomic operations. By sending concurrent requests, an attacker can use a single-use impersonation token multiple times before the database update completes. To make this work, an attacker needs to obtain a valid user account impersonation URL with a non-expired token via some other means and exploit a race condition while bypassing any rate-limiting rules in place. For this to be a privilege escalation, the impersonation URL must include a token for a user account with more permissions than the current user. Versions 4.16.19 and 5.8.23 patch the issue.
Weakness
The product checks the state of a resource before using that resource, but the resource’s state can change between the check and the use in a way that invalidates the results of the check.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Craft_cms | Craftcms | 4.5.0 (excluding) | 4.16.19 (excluding) |
| Craft_cms | Craftcms | 5.0.0 (excluding) | 5.8.23 (excluding) |
| Craft_cms | Craftcms | 4.5.0 (including) | 4.5.0 (including) |
| Craft_cms | Craftcms | 4.5.0-rc1 (including) | 4.5.0-rc1 (including) |
| Craft_cms | Craftcms | 5.0.0 (including) | 5.0.0 (including) |
| Craft_cms | Craftcms | 5.0.0-rc1 (including) | 5.0.0-rc1 (including) |