Unsafe handling of user-specified cookies in treq
treq is an HTTP library inspired by requests but written on top of Twisted's Agents. Treq's request methods (treq.get, treq.post, etc.) and treq.client.HTTPClient constructor accept cookies as a dictionary. Such cookies are not bound to a single domain, and are therefore sent to every domain ("supercookies"). This can potentially cause sensitive information to leak upon an HTTP redirect to a different domain., e.g. should https://example.com redirect to http://cloudstorageprovider.com the latter …