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.
https://usn.ubuntu.com/4127-2/
https://usn.ubuntu.com/4127-1/
https://security.netapp.com/advisory/ntap-20190404-0004/
https://security.gentoo.org/glsa/202003-26
https://seclists.org/bugtraq/2019/Oct/29
https://lists.debian.org/debian-lts-announce/2020/08/msg00034.html
https://lists.debian.org/debian-lts-announce/2020/07/msg00011.html
https://lists.debian.org/debian-lts-announce/2019/07/msg00011.html
https://lists.debian.org/debian-lts-announce/2019/06/msg00022.html
https://github.com/python/cpython/pull/11842
https://bugs.python.org/issue35907
https://access.redhat.com/errata/RHSA-2019:3520
https://access.redhat.com/errata/RHSA-2019:3335
https://access.redhat.com/errata/RHSA-2019:2030
https://access.redhat.com/errata/RHSA-2019:1700
http://www.securityfocus.com/bid/107549
http://packetstormsecurity.com/files/154927/Slackware-Security-Advisory-python-Updates.html
http://lists.opensuse.org/opensuse-security-announce/2019-06/msg00050.html
http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00092.html