From 9053014a7e2eba28d000881e0bb3cc1d6e6b2eea Mon Sep 17 00:00:00 2001
From: Damian Mooyman <damian@silverstripe.com>
Date: Tue, 10 Apr 2018 16:45:14 +1200
Subject: [PATCH] [ss-2018-008] Validate against malformed urls

---
 src/Control/Director.php           | 25 +++++++++++++++++++------
 tests/php/Control/DirectorTest.php |  4 ++++
 2 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/src/Control/Director.php b/src/Control/Director.php
index 316148578..88908ef6e 100644
--- a/src/Control/Director.php
+++ b/src/Control/Director.php
@@ -728,13 +728,26 @@ class Director implements TemplateGlobalProvider
      */
     public static function is_site_url($url)
     {
-        $urlHost = parse_url($url, PHP_URL_HOST);
-        $actualHost = parse_url(self::protocolAndHost(), PHP_URL_HOST);
-        if ($urlHost && $actualHost && $urlHost == $actualHost) {
-            return true;
-        } else {
-            return self::is_relative_url($url);
+        $parsedURL = parse_url($url);
+
+        // Validate user (disallow slashes)
+        if (!empty($parsedURL['user']) && strstr($parsedURL['user'], '\\')) {
+            return false;
         }
+        if (!empty($parsedURL['pass']) && strstr($parsedURL['pass'], '\\')) {
+            return false;
+        }
+
+        // Validate host[:port]
+        $actualHost = parse_url(self::protocolAndHost(), PHP_URL_HOST);
+        if (!empty($parsedURL['host'])
+            && $actualHost
+            && $parsedURL['host'] === $actualHost
+        ) {
+            return true;
+        }
+
+        return self::is_relative_url($url);
     }
 
     /**
diff --git a/tests/php/Control/DirectorTest.php b/tests/php/Control/DirectorTest.php
index eae00b2b8..9a1de2ec4 100644
--- a/tests/php/Control/DirectorTest.php
+++ b/tests/php/Control/DirectorTest.php
@@ -380,6 +380,10 @@ class DirectorTest extends SapphireTest
         $this->assertFalse(Director::is_site_url("http://test.com?url=" . Director::absoluteBaseURL()));
         $this->assertFalse(Director::is_site_url("http://test.com?url=" . urlencode(Director::absoluteBaseURL())));
         $this->assertFalse(Director::is_site_url("//test.com?url=" . Director::absoluteBaseURL()));
+        $this->assertFalse(Director::is_site_url('http://google.com\@test.com'));
+        $this->assertFalse(Director::is_site_url('http://google.com/@test.com'));
+        $this->assertFalse(Director::is_site_url('http://google.com:pass\@test.com'));
+        $this->assertFalse(Director::is_site_url('http://google.com:pass/@test.com'));
     }
 
     /**