Mozilla Thunderbird is vulnerable to unauthorised access. Proxy Auto-Configuration file can define localhost access to be proxied.
lists.opensuse.org/opensuse-security-announce/2019-03/msg00035.html
lists.opensuse.org/opensuse-security-announce/2019-03/msg00035.html
lists.opensuse.org/opensuse-security-announce/2019-03/msg00043.html
lists.opensuse.org/opensuse-security-announce/2019-03/msg00043.html
lists.opensuse.org/opensuse-security-announce/2019-04/msg00023.html
lists.opensuse.org/opensuse-security-announce/2019-04/msg00023.html
lists.opensuse.org/opensuse-security-announce/2019-04/msg00043.html
lists.opensuse.org/opensuse-security-announce/2019-04/msg00043.html
www.securityfocus.com/bid/106773
www.securityfocus.com/bid/106773
access.redhat.com/errata/RHSA-2019:0622
access.redhat.com/errata/RHSA-2019:0622
access.redhat.com/errata/RHSA-2019:0623
access.redhat.com/errata/RHSA-2019:0623
access.redhat.com/errata/RHSA-2019:0680
access.redhat.com/errata/RHSA-2019:0681
access.redhat.com/errata/RHSA-2019:0681
access.redhat.com/errata/RHSA-2019:0966
access.redhat.com/errata/RHSA-2019:0966
access.redhat.com/errata/RHSA-2019:1144
access.redhat.com/errata/RHSA-2019:1144
access.redhat.com/security/updates/classification/#important
lists.debian.org/debian-lts-announce/2019/03/msg00024.html
lists.debian.org/debian-lts-announce/2019/03/msg00024.html
lists.debian.org/debian-lts-announce/2019/04/msg00000.html
lists.debian.org/debian-lts-announce/2019/04/msg00000.html
seclists.org/bugtraq/2019/Apr/0
seclists.org/bugtraq/2019/Apr/0
seclists.org/bugtraq/2019/Mar/28
seclists.org/bugtraq/2019/Mar/28
security.gentoo.org/glsa/201904-07
security.gentoo.org/glsa/201904-07
usn.ubuntu.com/3874-1/
usn.ubuntu.com/3874-1/
usn.ubuntu.com/3927-1/
usn.ubuntu.com/3927-1/
www.debian.org/security/2019/dsa-4411
www.debian.org/security/2019/dsa-4411
www.debian.org/security/2019/dsa-4420
www.debian.org/security/2019/dsa-4420
www.mozilla.org/en-US/security/advisories/mfsa2019-11/
www.mozilla.org/en-US/security/advisories/mfsa2019-12/
www.mozilla.org/security/advisories/mfsa2019-01/
www.mozilla.org/security/advisories/mfsa2019-01/