XWiki is a generic wiki platform. In versions starting from 6.1-milestone-1 to before 15.10.12, from 16.0.0-rc-1 to before 16.4.3, and from 16.5.0-rc-1 to before 16.8.0-rc-1, the script API of the LESS compiler in XWiki is incorrectly checking for rights when calling the cache cleaning API, making it possible to clean the cache without having programming right. The only impact of this is a slowdown in XWiki execution as the caches are re-filled. As this vulnerability requires script right to exploit, and script right already allows unlimited execution of scripts, the additional impact due to this vulnerability is low. This issue has been patched in versions 15.10.12, 16.4.3, and 16.8.0-rc-1.
The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action.
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 not applied consistently - or not at all - 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.