diff --git a/typo3/sysext/core/Classes/Authentication/AbstractUserAuthentication.php b/typo3/sysext/core/Classes/Authentication/AbstractUserAuthentication.php
index 3ec45b9..ec85050 100644
--- a/typo3/sysext/core/Classes/Authentication/AbstractUserAuthentication.php
+++ b/typo3/sysext/core/Classes/Authentication/AbstractUserAuthentication.php
@@ -1170,7 +1170,9 @@ abstract class AbstractUserAuthentication {
 	 */
 	public function unpack_uc($theUC = '') {
 		if (!$theUC) {
-			$theUC = unserialize($this->user['uc']);
+			if (isset($this->user['uc'])) {
+				$theUC = unserialize($this->user['uc']);
+			}
 		}
 		if (is_array($theUC)) {
 			$this->uc = $theUC;
diff --git a/typo3/sysext/frontend/Classes/Authentication/FrontendUserAuthentication.php b/typo3/sysext/frontend/Classes/Authentication/FrontendUserAuthentication.php
index 8fa3b25..e2d1bd6 100644
--- a/typo3/sysext/frontend/Classes/Authentication/FrontendUserAuthentication.php
+++ b/typo3/sysext/frontend/Classes/Authentication/FrontendUserAuthentication.php
@@ -191,7 +191,7 @@ class FrontendUserAuthentication extends \TYPO3\CMS\Core\Authentication\Abstract
 	 * @todo Define visibility
 	 */
 	public function isSetSessionCookie() {
-		$retVal = ($this->newSessionID || $this->forceSetCookie) && ($this->lifetime == 0 || !$this->user['ses_permanent']);
+		$retVal = ($this->newSessionID || $this->forceSetCookie) && ($this->lifetime == 0 || !isset($this->user['ses_permanent']));
 		return $retVal;
 	}
 
@@ -203,7 +203,7 @@ class FrontendUserAuthentication extends \TYPO3\CMS\Core\Authentication\Abstract
 	 * @todo Define visibility
 	 */
 	public function isRefreshTimeBasedCookie() {
-		return $this->lifetime > 0 && $this->user['ses_permanent'];
+		return $this->lifetime > 0 && isset($this->user['ses_permanent']);
 	}
 
 	/**