CVE-2019-9948

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(‘local_file:///etc/passwd’) call.

Mitigation

If your application uses a blacklist to prevent "file://" schema from being used, consider using a whitelist approach to just allow the schemas you want or add "local_file://" schema to your blacklist.