Ticket #33999: 33999.patch

src/wp-admin/includes/file.php

@@ -168 +168 @@
                 $dir = get_temp_dir();
         }
 
-        if ( empty( $filename ) || '.' == $filename || '/' == $filename ) {
+        if ( empty( $filename ) || '.' == $filename || '/' == $filename || '\\' == $filename ) {
                 $filename = time();
         }