Gogs: Missing Authorization in Attachment Download

Gogs is an open source self-hosted Git service. Prior to 0.14.3, GET /attachments/:uuid returns the raw attachment file without verifying whether the requester has view permission for the associated Issue/Comment/Release or the repository. In a test environment with REQUIRE_SIGNIN_VIEW = false, we confirmed that an unauthenticated user can download attachments belonging to a private repository. This vulnerability is fixed in 0.14.3.