Fix filter bypass in filter_var FILTER_VALIDATE_URL

  CVE-2024-5458

1 files changed, 264 insertions, 0 deletions

diff --git a/php-cve-2024-5458.patch b/php-cve-2024-5458.patch
new file mode 100644
index 0000000..8f8e23c
--- /dev/null
+++ b/php-cve-2024-5458.patch
@@ -0,0 +1,264 @@
+From acadcd6a81bf11aacdc123fd241a5653c0f3605d 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)
+(cherry picked from commit 08be64e40197fc12dca5f802d16748d9c3cb4cb4)
+(cherry picked from commit 76362f9526afbd5565003d981f9507aaf62337f2)
+(cherry picked from commit 87a7b8dab75e221a1fcd74cf34dc650f7253c12c)
+(cherry picked from commit b919ad0323dbc3e1e1ac0f6ba8ec2ad380579918)
+(cherry picked from commit f232d87846394315071ae115fcb8f1c4d1771eb3)
+(cherry picked from commit 237878338b1cee3119e3f6d62c640b8cdb6d1169)
+---
+ ext/filter/logical_filters.c              | 93 +++++++++++++++++++----
+ ext/filter/tests/ghsa-w8qr-v226-r27w.phpt | 41 ++++++++++
+ 2 files changed, 119 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 92a37f88ee..39260f3622 100644
+--- a/ext/filter/logical_filters.c
++++ b/ext/filter/logical_filters.c
+@@ -66,6 +66,8 @@
+ #define FORMAT_IPV4    4
+ #define FORMAT_IPV6    6
+ 
++static int _php_filter_validate_ipv6(const char *str, int str_len TSRMLS_DC);
++
+ static int php_filter_parse_int(const char *str, unsigned int str_len, long *ret TSRMLS_DC) { /* {{{ */
+ 	long ctx_value;
+ 	int sign = 0, digit = 0;
+@@ -445,6 +447,58 @@ void php_filter_validate_regexp(PHP_INPUT_FILTER_PARAM_DECL) /* {{{ */
+ }
+ /* }}} */
+ 
++static int _php_filter_validate_domain(char * domain, int len) /* {{{ */
++{
++	char *e, *s, *t;
++	size_t l;
++	int hostname = 1;
++	unsigned char i = 1;
++
++	s = domain;
++	l = len;
++	e = domain + l;
++	t = e - 1;
++
++	/* Ignore trailing dot */
++	if (*t == '.') {
++		e = t;
++		l--;
++	}
++
++	/* The total length cannot exceed 253 characters (final dot not included) */
++	if (l > 253) {
++		return 0;
++	}
++
++	/* First char must be alphanumeric */
++	if(*s == '.' || (hostname && !isalnum((int)*(unsigned char *)s))) {
++		return 0;
++	}
++
++	while (s < e) {
++		if (*s == '.') {
++			/* The first and the last character of a label must be alphanumeric */
++			if (*(s + 1) == '.' || (hostname && (!isalnum((int)*(unsigned char *)(s - 1)) || !isalnum((int)*(unsigned char *)(s + 1))))) {
++				return 0;
++			}
++
++			/* Reset label length counter */
++			i = 1;
++		} else {
++			if (i > 63 || (hostname && *s != '-' && !isalnum((int)*(unsigned char *)s))) {
++				return 0;
++			}
++
++			i++;
++		}
++
++		s++;
++	}
++
++	return 1;
++}
++/* }}} */
++
+ static int is_userinfo_valid(char *str)
+ {
+ 	const char *valid = "-._~!$&'()*+,;=:";
+@@ -463,6 +517,14 @@ static int is_userinfo_valid(char *str)
+ 	return 1;
+ }
+ 
++static zend_bool php_filter_is_valid_ipv6_hostname(const char *s, size_t l TSRMLS_DC)
++{
++	const char *e = s + l;
++	const char *t = e - 1;
++
++	return *s == '[' && *t == ']' && _php_filter_validate_ipv6(s + 1, l - 2 TSRMLS_CC);
++}
++
+ void php_filter_validate_url(PHP_INPUT_FILTER_PARAM_DECL) /* {{{ */
+ {
+ 	php_url *url;
+@@ -482,25 +544,26 @@ void php_filter_validate_url(PHP_INPUT_FILTER_PARAM_DECL) /* {{{ */
+ 	}
+ 
+ 	if (url->scheme != NULL && (!strcasecmp(url->scheme, "http") || !strcasecmp(url->scheme, "https"))) {
+-		char *e, *s;
++		const char *s;
++		size_t l;
+ 
+ 		if (url->host == NULL) {
+ 			goto bad_url;
+ 		}
+ 
+-		e = url->host + strlen(url->host);
+ 		s = url->host;
++		l = strlen(s);
+ 
+-		/* First char of hostname must be alphanumeric */
+-		if(!isalnum((int)*(unsigned char *)s)) { 
+-			goto bad_url;
+-		}
++		if (
++			/* An IPv6 enclosed by square brackets is a valid hostname.*/
++			!php_filter_is_valid_ipv6_hostname(s, l TSRMLS_CC) &&
++			/* Validate domain.
++			 * This includes a loose check for an IPv4 address. */
++			!_php_filter_validate_domain(url->host, l)
+ 
+-		while (s < e) {
+-			if (!isalnum((int)*(unsigned char *)s) && *s != '-' && *s != '.') {
+-				goto bad_url;
+-			}
+-			s++;
++		) {
++			php_url_free(url);
++			RETURN_VALIDATION_FAILED
+ 		}
+ 	}
+ 
+@@ -581,7 +644,7 @@ void php_filter_validate_email(PHP_INPUT_FILTER_PARAM_DECL) /* {{{ */
+ }
+ /* }}} */
+ 
+-static int _php_filter_validate_ipv4(char *str, int str_len, int *ip) /* {{{ */
++static int _php_filter_validate_ipv4(const char *str, int str_len, int *ip) /* {{{ */
+ {
+ 	const char *end = str + str_len;
+ 	int num, m;
+@@ -616,15 +679,15 @@ static int _php_filter_validate_ipv4(char *str, int str_len, int *ip) /* {{{ */
+ }
+ /* }}} */
+ 
+-static int _php_filter_validate_ipv6(char *str, int str_len TSRMLS_DC) /* {{{ */
++static int _php_filter_validate_ipv6(const char *str, int str_len TSRMLS_DC) /* {{{ */
+ {
+ 	int compressed = 0;
+ 	int blocks = 0;
+ 	int n;
+ 	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 0000000000..97867d4b07
+--- /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($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 aa6e34b7cb4ea37d5f7cab27a560df8f0b763908 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)
+(cherry picked from commit ec1d5e6468479e64acc7fb8cb955f053b64ea9a0)
+(cherry picked from commit cfe1b1acead13b6af163f3ce947d3a1dbded82a0)
+(cherry picked from commit 6b6444a1b72d6249cfa592f20395efe67ca55f73)
+(cherry picked from commit 8d4db37794eff4761a336d7cee53d47f0eb0d313)
+(cherry picked from commit 573b921a612068f66f6540b69b0a9bc9f372ecf1)
+(cherry picked from commit 20ceeb85afad56df396a61247f2cb4cb9efb9a6b)
+---
+ NEWS | 6 ++++++
+ 1 file changed, 6 insertions(+)
+
+diff --git a/NEWS b/NEWS
+index 163bc6bdba..c10febbfa1 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
+