Cloudreve is a self-hosted file management and sharing system. From 4.12.0 until 4.16.1, Cloudreve's OAuth access tokens are issued without the OAuth client_id claim, so the JWT verifier does not load token scopes into request context and RequiredScopes treats the request like non-scoped session authentication, allowing a low-scope OAuth access token to call APIs requiring higher scopes such as file, share, workflow, user setting, WebDAV account, and potentially admin scopes. This issue is fixed in version 4.16.1.
Analyzing vulnerability vectors…