Fixed issue with blank password with Ldap

The bind operation of LDAP, as described in RFC 4513, provides a method
which allows for authentication of users. For the Simple Authentication
Method a user may use the anonymous authentication mechanism, the
unauthenticated authentication mechanism, or the name/password
authentication mechanism. The unauthenticated authentication mechanism
is used when a client who desires to establish an anonymous
authorization state passes a non-zero length distinguished name and a
zero length password. Most LDAP servers either can be configured to
allow this mechanism or allow it by default.

_Web-based applications which perform the simple bind operation with the
client's credentials are at risk when an anonymous authorization state is
established. This can occur when the web-based application passes a
distinguished name and a zero length password to the LDAP server._

Thus, misconfiguring a server with simple bind can trick Symfony into
thinking the username/password tuple as valid, potentially leading to
unauthorized access.

1 files changed, 4 insertions, 0 deletions

diff --git a/Core/Authentication/Provider/LdapBindAuthenticationProvider.php b/Core/Authentication/Provider/LdapBindAuthenticationProvider.php
index adc42ef..e887f99 100644
--- a/Core/Authentication/Provider/LdapBindAuthenticationProvider.php
+++ b/Core/Authentication/Provider/LdapBindAuthenticationProvider.php
@@ -73,6 +73,10 @@ class LdapBindAuthenticationProvider extends UserAuthenticationProvider
         $username = $token->getUsername();
         $password = $token->getCredentials();
 
+        if ('' === $password) {
+            throw new BadCredentialsException('The presented password must not be empty.');
+        }
+
         try {
             $username = $this->ldap->escape($username, '', LDAP_ESCAPE_DN);
             $dn = str_replace('{username}', $username, $this->dnString);