From: ismail1432 <smaine.milianni@gmail.com>
Date: Sun, 18 Mar 2018 14:56:17 +0100
Subject: [Ldap] cast to string when checking empty passwords

[CVE-2016-2403] https://symfony.com/blog/cve-2016-2403-unauthorized-access-on-a-misconfigured-ldap-server-when-using-an-empty-password

Origin: upstream, https://github.com/symfony/symfony/commit/f276989b489d8975d06aee7e43ead70f326d3bc0
---
 .../Provider/LdapBindAuthenticationProvider.php         |  2 +-
 .../Provider/LdapBindAuthenticationProviderTest.php     | 17 +++++++++++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/src/Symfony/Component/Security/Core/Authentication/Provider/LdapBindAuthenticationProvider.php b/src/Symfony/Component/Security/Core/Authentication/Provider/LdapBindAuthenticationProvider.php
index e887f99..5196890 100644
--- a/src/Symfony/Component/Security/Core/Authentication/Provider/LdapBindAuthenticationProvider.php
+++ b/src/Symfony/Component/Security/Core/Authentication/Provider/LdapBindAuthenticationProvider.php
@@ -73,7 +73,7 @@ class LdapBindAuthenticationProvider extends UserAuthenticationProvider
         $username = $token->getUsername();
         $password = $token->getCredentials();
 
-        if ('' === $password) {
+        if ('' === (string) $password) {
             throw new BadCredentialsException('The presented password must not be empty.');
         }
 
diff --git a/src/Symfony/Component/Security/Core/Tests/Authentication/Provider/LdapBindAuthenticationProviderTest.php b/src/Symfony/Component/Security/Core/Tests/Authentication/Provider/LdapBindAuthenticationProviderTest.php
index fbb4d73..03189a6 100644
--- a/src/Symfony/Component/Security/Core/Tests/Authentication/Provider/LdapBindAuthenticationProviderTest.php
+++ b/src/Symfony/Component/Security/Core/Tests/Authentication/Provider/LdapBindAuthenticationProviderTest.php
@@ -38,6 +38,23 @@ class LdapBindAuthenticationProviderTest extends \PHPUnit_Framework_TestCase
         $reflection->invoke($provider, new User('foo', null), new UsernamePasswordToken('foo', '', 'key'));
     }
 
+    /**
+     * @expectedException        \Symfony\Component\Security\Core\Exception\BadCredentialsException
+     * @expectedExceptionMessage The presented password must not be empty.
+     */
+    public function testNullPasswordShouldThrowAnException()
+    {
+        $userProvider = $this->getMockBuilder('Symfony\Component\Security\Core\User\UserProviderInterface')->getMock();
+        $ldap = $this->getMockBuilder('Symfony\Component\Ldap\LdapClientInterface')->getMock();
+        $userChecker = $this->getMockBuilder('Symfony\Component\Security\Core\User\UserCheckerInterface')->getMock();
+
+        $provider = new LdapBindAuthenticationProvider($userProvider, $userChecker, 'key', $ldap);
+        $reflection = new \ReflectionMethod($provider, 'checkAuthentication');
+        $reflection->setAccessible(true);
+
+        $reflection->invoke($provider, new User('foo', null), new UsernamePasswordToken('foo', null, 'key'));
+    }
+
     /**
      * @expectedException        \Symfony\Component\Security\Core\Exception\BadCredentialsException
      * @expectedExceptionMessage The presented password is invalid.