ext/phar/phar_object.c in PHP before 5.5.32 5.6.x before 5.6.18 and 7.x before 7.0.3 mishandles zero-length uncompressed data which allows remote attackers to cause a denial of service (heap memory corruption) or possibly have unspecified other impact via a crafted (1) TAR (2) ZIP or (3) PHAR archive.