PHP Web Statistik 1.4 does not rotate the log database or limit the size of the referer field, which allows remote attackers to fill the log files via a large number of requests, as demonstrated using pixel.php.
https://exchange.xforce.ibmcloud.com/vulnerabilities/23386
http://www.ush.it/2005/11/19/php-web-statistik/
http://securityreason.com/securityalert/214
http://freewebstat.com/changelog-english.html
http://cert.uni-stuttgart.de/archive/bugtraq/2005/11/msg00325.html