Integer overflow in the ftp_genlist function in ext/ftp/ftp.c in PHP before 5.4.42, 5.5.x before 5.5.26, and 5.6.x before 5.6.10 allows remote FTP servers to execute arbitrary code via a long reply to a LIST command, leading to a heap-based buffer overflow.  NOTE: this vulnerability exists because of an incomplete fix for CVE-2015-4022.