diff --git a/framework/yii/rbac/Manager.php b/framework/yii/rbac/Manager.php
index a1bf47a..2f392c5 100644
--- a/framework/yii/rbac/Manager.php
+++ b/framework/yii/rbac/Manager.php
@@ -21,7 +21,7 @@ use yii\base\InvalidParamException;
  * Access Control (RBAC).
  *
  * The main idea is that permissions are organized as a hierarchy of
- * [[Item]] authorization items. Items on higer level inherit the permissions
+ * [[Item]] authorization items. Items on higher level inherit the permissions
  * represented by items on lower level. And roles are simply top-level authorization items
  * that may be assigned to individual users. A user is said to have a permission
  * to do something if the corresponding authorization item is inherited by one of his roles.
diff --git a/framework/yii/web/Request.php b/framework/yii/web/Request.php
index ef005be..717f403 100644
--- a/framework/yii/web/Request.php
+++ b/framework/yii/web/Request.php
@@ -577,7 +577,7 @@ class Request extends \yii\base\Request
 			$pathInfo = substr($pathInfo, strlen($scriptUrl));
 		} elseif ($baseUrl === '' || strpos($pathInfo, $baseUrl) === 0) {
 			$pathInfo = substr($pathInfo, strlen($baseUrl));
-		} elseif (strpos($_SERVER['PHP_SELF'], $scriptUrl) === 0) {
+		} elseif (isset($_SERVER['PHP_SELF']) && strpos($_SERVER['PHP_SELF'], $scriptUrl) === 0) {
 			$pathInfo = substr($_SERVER['PHP_SELF'], strlen($scriptUrl));
 		} else {
 			throw new InvalidConfigException('Unable to determine the path info of the current request.');