A security regression of CVE-2019-9636 was discovered in python, since commit d537ab0ff9767ef024f26246899728f0116b1ec3, which still allows an attacker to exploit CVE-2019-9636 by abusing the user and password parts of a URL. When an application parses user-supplied URLs to store cookies, authentication credentials, or other kind of information, it is possible for an attacker to provide specially crafted URLs to make the application locate host-related information and send them to a different host than where it should, unlike if the URLs had been correctly parsed. The result of an attack may vary based on the application.urllib in Python 2.x through 2.7.16 supports the local_file: scheme, which makes it easier for remote attackers to bypass protection mechanisms that blacklist file: URIs, as demonstrated by triggering a urllib.urlopen call.