When PHP EXIF extension is parsing EXIF information from an image, e.g. via exif_read_data() function, in PHP versions 7.1.x below 7.1.30, 7.2.x below 7.2.19 and 7.3.x below 7.3.6 it is possible to supply it with data what will cause it to read past the allocated buffer. This may lead to information disclosure or crash.
lists.opensuse.org/opensuse-security-announce/2019-07/msg00029.html
access.redhat.com/errata/RHSA-2019:2519
access.redhat.com/errata/RHSA-2019:3299
bugs.php.net/bug.php?id=77988
seclists.org/bugtraq/2019/Sep/35
seclists.org/bugtraq/2019/Sep/38
www.debian.org/security/2019/dsa-4527
www.debian.org/security/2019/dsa-4529