Fix filter bypass in filter_var FILTER_VALIDATE_URL

  CVE-2024-5458

1 files changed, 180 insertions, 0 deletions

diff --git a/php-cve-2024-5458.patch b/php-cve-2024-5458.patch
new file mode 100644
index 0000000..64a1a78
--- /dev/null
+++ b/php-cve-2024-5458.patch
@@ -0,0 +1,180 @@
+From 08be64e40197fc12dca5f802d16748d9c3cb4cb4 Mon Sep 17 00:00:00 2001
+From: Niels Dossche <7771979+nielsdos@users.noreply.github.com>
+Date: Wed, 22 May 2024 22:25:02 +0200
+Subject: [PATCH 1/2] Fix GHSA-w8qr-v226-r27w
+
+We should not early-out with success status if we found an ipv6
+hostname, we should keep checking the rest of the conditions.
+Because integrating the if-check of the ipv6 hostname in the
+"Validate domain" if-check made the code hard to read, I extracted the
+condition out to a separate function. This also required to make
+a few pointers const in order to have some clean code.
+
+(cherry picked from commit 4066610b47e22c24cbee91be434a94357056a479)
+---
+ ext/filter/logical_filters.c              | 35 ++++++++++---------
+ ext/filter/tests/ghsa-w8qr-v226-r27w.phpt | 41 +++++++++++++++++++++++
+ 2 files changed, 61 insertions(+), 15 deletions(-)
+ create mode 100644 ext/filter/tests/ghsa-w8qr-v226-r27w.phpt
+
+diff --git a/ext/filter/logical_filters.c b/ext/filter/logical_filters.c
+index e5e87c01568..9c86ad072cc 100644
+--- a/ext/filter/logical_filters.c
++++ b/ext/filter/logical_filters.c
+@@ -91,7 +91,7 @@
+ #define FORMAT_IPV4    4
+ #define FORMAT_IPV6    6
+ 
+-static int _php_filter_validate_ipv6(char *str, size_t str_len, int ip[8]);
++static int _php_filter_validate_ipv6(const char *str, size_t str_len, int ip[8]);
+ 
+ static int php_filter_parse_int(const char *str, size_t str_len, zend_long *ret) { /* {{{ */
+ 	zend_long ctx_value;
+@@ -571,6 +571,14 @@ static int is_userinfo_valid(zend_string *str)
+ 	return 1;
+ }
+ 
++static zend_bool php_filter_is_valid_ipv6_hostname(const char *s, size_t l)
++{
++	const char *e = s + l;
++	const char *t = e - 1;
++
++	return *s == '[' && *t == ']' && _php_filter_validate_ipv6(s + 1, l - 2, NULL);
++}
++
+ void php_filter_validate_url(PHP_INPUT_FILTER_PARAM_DECL) /* {{{ */
+ {
+ 	php_url *url;
+@@ -596,7 +604,7 @@ void php_filter_validate_url(PHP_INPUT_FILTER_PARAM_DECL) /* {{{ */
+ 
+ 	if (url->scheme != NULL &&
+ 		(zend_string_equals_literal_ci(url->scheme, "http") || zend_string_equals_literal_ci(url->scheme, "https"))) {
+-		char *e, *s, *t;
++		const char *s;
+ 		size_t l;
+ 
+ 		if (url->host == NULL) {
+@@ -605,17 +613,14 @@ void php_filter_validate_url(PHP_INPUT_FILTER_PARAM_DECL) /* {{{ */
+ 
+ 		s = ZSTR_VAL(url->host);
+ 		l = ZSTR_LEN(url->host);
+-		e = s + l;
+-		t = e - 1;
+-
+-		/* An IPv6 enclosed by square brackets is a valid hostname */
+-		if (*s == '[' && *t == ']' && _php_filter_validate_ipv6((s + 1), l - 2, NULL)) {
+-			php_url_free(url);
+-			return;
+-		}
+ 
+-		// Validate domain
+-		if (!_php_filter_validate_domain(ZSTR_VAL(url->host), l, FILTER_FLAG_HOSTNAME)) {
++		if (
++			/* An IPv6 enclosed by square brackets is a valid hostname.*/
++			!php_filter_is_valid_ipv6_hostname(s, l) &&
++			/* Validate domain.
++			 * This includes a loose check for an IPv4 address. */
++			!_php_filter_validate_domain(ZSTR_VAL(url->host), l, FILTER_FLAG_HOSTNAME)
++		) {
+ 			php_url_free(url);
+ 			RETURN_VALIDATION_FAILED
+ 		}
+@@ -749,15 +754,15 @@ static int _php_filter_validate_ipv4(char *str, size_t str_len, int *ip) /* {{{
+ }
+ /* }}} */
+ 
+-static int _php_filter_validate_ipv6(char *str, size_t str_len, int ip[8]) /* {{{ */
++static int _php_filter_validate_ipv6(const char *str, size_t str_len, int ip[8]) /* {{{ */
+ {
+ 	int compressed_pos = -1;
+ 	int blocks = 0;
+ 	int num, n, i;
+ 	char *ipv4;
+-	char *end;
++	const char *end;
+ 	int ip4elm[4];
+-	char *s = str;
++	const char *s = str;
+ 
+ 	if (!memchr(str, ':', str_len)) {
+ 		return 0;
+diff --git a/ext/filter/tests/ghsa-w8qr-v226-r27w.phpt b/ext/filter/tests/ghsa-w8qr-v226-r27w.phpt
+new file mode 100644
+index 00000000000..0092408ee5a
+--- /dev/null
++++ b/ext/filter/tests/ghsa-w8qr-v226-r27w.phpt
+@@ -0,0 +1,41 @@
++--TEST--
++GHSA-w8qr-v226-r27w
++--EXTENSIONS--
++filter
++--FILE--
++<?php
++
++function test(string $input) {
++    var_dump(filter_var($input, FILTER_VALIDATE_URL));
++}
++
++echo "--- These ones should fail ---\n";
++test("http://t[est@127.0.0.1");
++test("http://t[est@[::1]");
++test("http://t[est@[::1");
++test("http://t[est@::1]");
++test("http://php.net\\@aliyun.com/aaa.do");
++test("http://test[@2001:db8:3333:4444:5555:6666:1.2.3.4]");
++test("http://te[st@2001:db8:3333:4444:5555:6666:1.2.3.4]");
++test("http://te[st@2001:db8:3333:4444:5555:6666:1.2.3.4");
++
++echo "--- These ones should work ---\n";
++test("http://test@127.0.0.1");
++test("http://test@[2001:db8:3333:4444:5555:6666:1.2.3.4]");
++test("http://test@[::1]");
++
++?>
++--EXPECT--
++--- These ones should fail ---
++bool(false)
++bool(false)
++bool(false)
++bool(false)
++bool(false)
++bool(false)
++bool(false)
++bool(false)
++--- These ones should work ---
++string(21) "http://test@127.0.0.1"
++string(50) "http://test@[2001:db8:3333:4444:5555:6666:1.2.3.4]"
++string(17) "http://test@[::1]"
+-- 
+2.45.1
+
+From ec1d5e6468479e64acc7fb8cb955f053b64ea9a0 Mon Sep 17 00:00:00 2001
+From: Remi Collet <remi@remirepo.net>
+Date: Tue, 4 Jun 2024 16:48:08 +0200
+Subject: [PATCH 2/2] NEWS
+
+(cherry picked from commit a1ff81b786bd519597e770795be114f5171f0648)
+---
+ NEWS | 6 ++++++
+ 1 file changed, 6 insertions(+)
+
+diff --git a/NEWS b/NEWS
+index 8058eff0256..34ad33cf5c4 100644
+--- a/NEWS
++++ b/NEWS
+@@ -1,6 +1,12 @@
+ PHP                                                                        NEWS
+ |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
+ 
++Backported from 8.1.29
++
++- Filter:
++  . Fixed bug GHSA-w8qr-v226-r27w (Filter bypass in filter_var FILTER_VALIDATE_URL).
++    (CVE-2024-5458) (nielsdos)
++
+ Backported from 8.1.28
+ 
+ - Standard:
+-- 
+2.45.1
+