diff --git a/webui/model/user/auth.php b/webui/model/user/auth.php
index ad492a39..1963565f 100644
--- a/webui/model/user/auth.php
+++ b/webui/model/user/auth.php
@@ -212,9 +212,7 @@ class ModelUserAuth extends Model {
 
             if($ldap_auth->is_bind_ok()) {
 
-               $a['dn'] = stripslashes($a['dn']);
-               $a['dn'] = preg_replace("/\(/", '\(', $a['dn']);
-               $a['dn'] = preg_replace("/\)/", '\)', $a['dn']);
+               $a['dn'] = $this->escapeLdapFilter($a['dn']);
 
                $query = $ldap->query($ldap_base_dn, "(|(&(objectClass=$ldap_account_objectclass)($ldap_mail_attr=$username_prefix$username))(&(objectClass=$ldap_distributionlist_objectclass)($ldap_distributionlist_attr=$username_prefix$username)" . ")(&(objectClass=$ldap_distributionlist_objectclass)($ldap_distributionlist_attr=" . $a['dn'] . ")))", array());
 
@@ -538,6 +536,42 @@ class ModelUserAuth extends Model {
       return $rc;
    }
 
+
+   /*
+    * For more explanation, see https://bitbucket.org/jsuto/piler/issues/679/get-mailing-list-members-from-active
+    * Credits: Thoth
+    */
+
+   public function escapeLdapFilter($str = '') {
+      // The characters that need to be escape.
+      //
+      // NOTE: It's important that the slash is the first character replaced.
+      // Otherwise the slash added by other replacements will then be
+      // replaced as well, resulted in double-escaping all characters
+      // replaced before the slashes were replaced.
+      //
+      $metaChars = array(
+                          chr(0x5c), // \
+                          chr(0x2a), // *
+                          chr(0x28), // (
+                          chr(0x29), // )
+                          chr(0x00) // NUL
+                       );
+
+        // Build the list of the escaped versions of those characters.
+
+        $quotedMetaChars = array();
+
+        foreach ($metaChars as $key => $value) {
+           $quotedMetaChars[$key] = '\\' .
+           str_pad(dechex(ord($value)), 2, '0', STR_PAD_LEFT);
+        }
+
+        // Make all the necessary replacements in the input string and return
+        // the result.
+
+        return str_replace($metaChars, $quotedMetaChars, $str);
+    }
 }
 
 ?>