Multiple integer overflows in ext/standard/exec.c in PHP 7.x before 7.0.2 allow remote attackers to cause a denial of service or possibly have unspecified other impact via a long string to the (1) php_escape_shell_cmd or (2) php_escape_shell_arg function, leading to a heap-based buffer overflow.
https://github.com/php/php-src/commit/2871c70efaaaa0f102557a17c727fd4d5204dd4b
http://www.securitytracker.com/id/1034608