From a5538c62293fa782fcc382d0635cfc0c8b9190e3 Mon Sep 17 00:00:00 2001
From: "Christoph M. Becker" <cmbecker69@gmx.de>
Date: Mon, 14 Jun 2021 13:22:27 +0200
Subject: [PATCH] Fix #81122: SSRF bypass in FILTER_VALIDATE_URL

We need to ensure that the password detected by parse_url() is actually
a valid password; we can re-use is_userinfo_valid() for that.
---
 ext/filter/logical_filters.c   |  4 +++-
 ext/filter/tests/bug81122.phpt | 21 +++++++++++++++++++++
 2 files changed, 24 insertions(+), 1 deletion(-)
 create mode 100644 ext/filter/tests/bug81122.phpt

diff --git a/ext/filter/logical_filters.c b/ext/filter/logical_filters.c
index 1cf345dbb58a..3f314fefa0e1 100644
--- a/ext/filter/logical_filters.c
+++ b/ext/filter/logical_filters.c
@@ -609,7 +609,9 @@ void php_filter_validate_url(PHP_INPUT_FILTER_PARAM_DECL) /* {{{ */
 		RETURN_VALIDATION_FAILED
 	}
 
-	if (url->user != NULL && !is_userinfo_valid(url->user)) {
+	if (url->user != NULL && !is_userinfo_valid(url->user)
+		|| url->pass != NULL && !is_userinfo_valid(url->pass)
+	) {
 		php_url_free(url);
 		RETURN_VALIDATION_FAILED
 
diff --git a/ext/filter/tests/bug81122.phpt b/ext/filter/tests/bug81122.phpt
new file mode 100644
index 000000000000..d89d4114a547
--- /dev/null
+++ b/ext/filter/tests/bug81122.phpt
@@ -0,0 +1,21 @@
+--TEST--
+Bug #81122 (SSRF bypass in FILTER_VALIDATE_URL)
+--SKIPIF--
+<?php
+if (!extension_loaded('filter')) die("skip filter extension not available");
+?>
+--FILE--
+<?php
+$urls = [
+    "https://example.com:\\@test.com/",
+    "https://user:\\epass@test.com",
+    "https://user:\\@test.com",
+];
+foreach ($urls as $url) {
+    var_dump(filter_var($url, FILTER_VALIDATE_URL));
+}
+?>
+--EXPECT--
+bool(false)
+bool(false)
+bool(false)
-- 
2.27.0

