Ckan remote code execution and private information access via crafted resource ids

Specific vulnerabilities: * Arbitrary file write in `resource_create` and `package_update` actions, using the `ResourceUploader` object. Also reachable via `package_create`, `package_revise`, and `package_patch` via calls to `package_update`. * Remote code execution via unsafe pickle loading, via Beaker's session store when configured to use the file session store backend. * Potential DOS due to lack of a length check on the resource id. * Information disclosure: A user with permission to create a resource can access any other resource on the system if they know the id, even if they don't have access to it. * Resource overwrite: A user with permission to create a resource can overwrite any resource if they know the id, even if they don't have access to it. ### Impact A user with permissions to create or edit a dataset can upload a resource with a specially crafted id to write the uploaded file in an arbitrary location. This can be leveraged to Remote Code Execution via Beaker's insecure pickle loading. ### Patches All the above listed vulnerabilities have been fixed in CKAN 2.9.9 and CKAN 2.10.1 The patches for CKAN 2.9 should apply easily to previous CKAN versions.