CVE-2017-7272 (C, published 2017-03-27T17:59Z)
Description: value: 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.
Severity: MEDIUM (CVSS v3 base score: 7.4)
Weakness: CWE-918 \u2014 Server-Side Request Forgery (SSRF)
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.
Repository: https://github.com/php/php-src
Files changed:
ext/standard/tests/streams/parseip-001.phpt
main/streams/xp_socket.c
Commit message: Detect invalid port in xp_socket parse ip address

For historical reasons, fsockopen() accepts the port and hostname
separately: fsockopen('127.0.0.1', 80)

However, with the introdcution of stream transports in PHP 4.3,
it became possible to include the port in the hostname specifier:

fsockopen('127.0.0.1:80')
Or more formally: fsockopen('tcp://127.0.0.1:80')

Confusing results when these two forms are combined, however.
fsockopen('127.0.0.1:80', 443) results in fsockopen() attempting
to connect to '127.0.0.1:80:443' which any reasonable stack would
consider invalid.

Unfortunately, PHP parses the address looking for the first colon
(with special handling for IPv6, don't worry) and calls atoi()
from there.  atoi() in turn, simply stops parsing at the first
non-numeric character and returns the value so far.

The end result is that the explicitly supplied port is treated
as ignored garbage, rather than producing an error.

This diff replaces atoi() with strtol() and inspects the
stop character.  If additional "garbage" of any kind is found,
it fails and returns an error.


Vulnerable code:
	char *p;

		p = memchr(str + 1, ']', str_len - 2);
		*portno = atoi(p + 2);
		*portno = atoi(colon + 1);
		host = estrndup(str, colon - str);
	} else {
		if (get_err) {
			*err = strpprintf(0, "Failed to parse address \"%s\"", str);
		return NULL;
	return host;

Fixed code:
--TEST--
Use of double-port in fsockopen()
--FILE--
<?php

$try = [
  '127.0.0.1:80',
  'tcp://127.0.0.1:80',
  '[::1]:80',
  'tcp://[::1]:80',
  'localhost:80',
  'tcp://localhost:80',
];

foreach ($try as $addr) {
  echo "== $addr ==\n";
  var_dump(@fsockopen($addr, 81, $errno, $errstr), $errstr);
}
--EXPECTF--
== 127.0.0.1:80 ==
bool(false)
string(41) "Failed to parse address "127.0.0.1:80:81""
== tcp://127.0.0.1:80 ==
bool(false)
string(41) "Failed to parse address "127.0.0.1:80:81""
== [::1]:80 ==
bool(false)
string(37) "Failed to parse address "[::1]:80:81""
== tcp://[::1]:80 ==
bool(false)
string(37) "Failed to parse address "[::1]:80:81""
== localhost:80 ==
bool(false)
string(41) "Failed to parse address "localhost:80:81""
== tcp://localhost:80 ==
bool(false)
string(41) "Failed to parse address "localhost:80:81""
		char *p = memchr(str + 1, ']', str_len - 2), *e = NULL;
		*portno = strtol(p + 2, &e, 10);
		if (e && *e) {
			if (get_err) {
				*err = strpprintf(0, "Failed to parse address \"%s\"", str);
			}
			return NULL;
		}


		char *e = NULL;
		*portno = strtol(colon + 1, &e, 10);
		if (!e || !*e) {
			return estrndup(str, colon - str);
	if (get_err) {
		*err = strpprintf(0, "Failed to parse address \"%s\"", str);
	}
	return NULL;