In PHP through 5.6.33, 7.0.x before 7.0.28, 7.1.x through 7.1.14, and 7.2.x through 7.2.2, there is a stack-based buffer under-read while parsing an HTTP response in the php_stream_url_wrap_http_ex function in ext/standard/http_fopen_wrapper.c. This subsequently results in copying a large string.
php.net/ChangeLog-7.php
www.securityfocus.com/bid/103204
www.securitytracker.com/id/1041607
access.redhat.com/errata/RHSA-2019:2519
bugs.php.net/bug.php?id=75981
github.com/php/php-src/commit/523f230c831d7b33353203fa34aee4e92ac12bba
lists.debian.org/debian-lts-announce/2018/03/msg00030.html
lists.debian.org/debian-lts-announce/2018/06/msg00005.html
usn.ubuntu.com/3600-1/
usn.ubuntu.com/3600-2/
www.debian.org/security/2018/dsa-4240
www.exploit-db.com/exploits/44846/
www.tenable.com/security/tns-2018-03
www.tenable.com/security/tns-2018-12