awstats.pl in AWStats 6.5 build 1.857 and earlier allows remote attackers to obtain the installation path via the (1) year, (2) pluginmode or (3) month parameters.
https://exchange.xforce.ibmcloud.com/vulnerabilities/25880
http://www.vupen.com/english/advisories/2006/1421
http://www.ubuntu.com/usn/usn-360-1
http://secunia.com/advisories/22306
http://pridels0.blogspot.com/2006/04/awstats-65x-multiple-vuln.html