PHP Server-Side Request Forgery (SSRF) Vulnerability - CVE-2017-7272
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.