diff --git a/apps/dav/lib/CardDAV/CardDavBackend.php b/apps/dav/lib/CardDAV/CardDavBackend.php
index f7d0a888efd..b44fd37f488 100644
--- a/apps/dav/lib/CardDAV/CardDavBackend.php
+++ b/apps/dav/lib/CardDAV/CardDavBackend.php
@@ -519,6 +519,7 @@ class CardDavBackend implements BackendInterface, SyncSupport {
 		$result = $query->executeQuery();
 		$row = $result->fetch();
 		if (!$row) {
+			$result->closeCursor();
 			return false;
 		}
 		$row['etag'] = '"' . $row['etag'] . '"';
@@ -528,6 +529,7 @@ class CardDavBackend implements BackendInterface, SyncSupport {
 		if ($modified) {
 			$row['size'] = strlen($row['carddata']);
 		}
+		$result->closeCursor();
 
 		return $row;
 	}
@@ -974,7 +976,12 @@ class CardDavBackend implements BackendInterface, SyncSupport {
 	 */
 	private function readBlob($cardData, &$modified = false) {
 		if (is_resource($cardData)) {
-			$cardData = stream_get_contents($cardData);
+			$stringCardData = stream_get_contents($cardData);
+			if ($stringCardData === false) {
+				return '';
+			}
+			fclose($cardData);
+			$cardData = $stringCardData;
 		}
 
 		// Micro optimisation