exif_process_IFD_in_MAKERNOTE in ext/exif/exif.c in PHP before 5.6.37, 7.0.x before 7.0.31, 7.1.x before 7.1.20, and 7.2.x before 7.2.8 allows remote attackers to cause a denial of service (out-of-bounds read and application crash) via a crafted JPEG file.