Zulip is an open-source team chat application. Starting in version 10.0 and prior to version 10.3, the Who can create public channels access control mechanism can be circumvented by creating a private or web-public channel, and then changing the channel privacy to public. A similar technique works for creating private channels without permission, though such a process requires either the API or modifying the HTML, as we do mark the private radio button as disabled in such cases. Version 10.3 contains a patch.
The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. This allows attackers to bypass intended access restrictions.
Name | Vendor | Start Version | End Version |
---|---|---|---|
Zulip | Zulip | 10.0 (including) | 10.3 (excluding) |
Assuming a user with a given identity, authorization is the process of determining whether that user can access a given resource, based on the user’s privileges and any permissions or other access-control specifications that apply to the resource. When access control checks are incorrectly applied, users are able to access data or perform actions that they should not be allowed to perform. This can lead to a wide range of problems, including information exposures, denial of service, and arbitrary code execution.