Livewire: Authorization bypass in #[Authorize] via reordered parameter keys and #[Json] execution order

An attacker could bypass authorisation on Livewire methods protected by #[Authorize] that take model parameters, including event listeners, and act on records they are not authorised to access. Methods using both #[Json] and #[Authorize] could also run before authorisation, allowing side effects such as database writes even though the response was 403. Only applications using #[Authorize] in these ways are affected.

Look in composer.lock for livewire/livewire at version >= 4.3.0, < 4.4.8. If present, check for #[Authorize] on methods that take model parameters, including listeners also marked #[On], or on methods also marked #[Json]. Authorisation performed inside the method with $this->authorize(...) is not affected. Livewire 3.x is not affected; the fix is in 4.4.8.

Upgrade to 4.4.8. If you cannot upgrade straight away, call $this->authorize(...) inside affected methods instead of relying on #[Authorize].

Impact

Three issues allowed actions protected by the #[Authorize] attribute to run against records the current user is not authorized for:

1. Out-of-order parameter keys on actions. #[Authorize] resolved a model parameter by its array key, while the action itself received parameters positionally. A request sending params as an object with reordered integer keys (e.g. {"1": 2, "0": 1}) could pass authorization with a record the user owns while the action received a different record. With #[Authorize('delete', 'comment')] on deleteComment(Comment $comment), a user could delete another user's comment.
2. The same issue on event listeners. Methods using both #[On] and #[Authorize] with a model parameter were affected in the same way through the __dispatch call.
3. #[Json] methods ran before authorization. When a method had both #[Json] and #[Authorize], the method body executed before the authorization check. The response was still a 403, but any side effects (such as database writes) had already happened.

Only applications using the #[Authorize] attribute are affected: on methods that take model parameters (issues 1 and 2), or on #[Json] methods (issue 3). Authorization performed inside the method (e.g. $this->authorize(...)) is not affected. Livewire 3.x is not affected.

Patches

Fixed in v4.4.8. Call and event parameters must now be a list or use named (string) keys, otherwise the request is rejected, and #[Json] methods are authorized before they run.

Workarounds

Upgrade to v4.4.8. If you can't upgrade right away, call $this->authorize(...) inside affected methods instead of relying on the #[Authorize] attribute.

Credits

Reported by Yousef Aman (@yousef-aman).