varnish 3.0.3 uses world-readable permissions for the /var/log/varnish/ directory and the log files in the directory, which allows local users to obtain sensitive information by reading the files. NOTE: some of these details are obtained from third party information.
https://euvd.enisa.europa.eu/vulnerability/EUVD-2013-0356
http://www.securityfocus.com/bid/58125