PHP through 7.1.11 enables potential SSRF in applications that accept an fsockopen or pfsockopen hostname argument with an expectation that the port number is constrained. Because a :port syntax is recognized, fsockopen will use the port number that is specified in the hostname argument, instead of the port number in the second argument of the function.
www.securityfocus.com/bid/97178
www.securitytracker.com/id/1038158
bugs.php.net/bug.php?id=74216
bugs.php.net/bug.php?id=75505
github.com/php/php-src/commit/bab0b99f376dac9170ac81382a5ed526938d595a
security.netapp.com/advisory/ntap-20180112-0001/
www.sec-consult.com/fxdata/seccons/prod/temedia/advisories_txt/20170403-0_PHP_Misbehavior_of_fsockopen_function_v10.txt