Disallow URLs containing a @

lib/base.php

@@ -631,8 +631,13 @@ class OC {
 		// Handle redirect URL for logged in users
 		if (isset($_REQUEST['redirect_url']) && OC_User::isLoggedIn()) {
 			$location = OC_Helper::makeURLAbsolute(urldecode($_REQUEST['redirect_url']));
-			header('Location: ' . $location);
-			return;
+			
+			// Deny the redirect if the URL contains a @
+			// This prevents unvalidated redirects like ?redirect_url=:user@domain.com
+			if (strpos($location, '@') === FALSE) {
+				header('Location: ' . $location);
+				return;
+			}
 		}
 		// Handle WebDAV
 		if ($_SERVER['REQUEST_METHOD'] == 'PROPFIND') {