On unix-like systems, the temporary directory is shared between all user. As such, writing to this directory using APIs that do not explicitly set the file/directory permissions can lead to information disclosure. Of note, this does not impact modern MacOS Operating Systems. The method File.createTempFile on unix-like systems creates a file with predefined name (so easily identifiable) and by default will create this file with the permissions -rw-r--r--. Thus, if sensitive information is written to this file, other local users can read this information. File.createTempFile(String, String) will create a temporary file in the system temporary directory if the 'java.io.tmpdir' system property is not explicitly set. This affects the class  https://github.com/apache/storm/blob/master/storm-core/src/jvm/org/apache/storm/utils/TopologySpoutLag.java#L99  and was introduced by  https://issues.apache.org/jira/browse/STORM-3123 In practice, this has a very limited impact as this class is u…