Directory traversal vulnerability in cal_make.pl in PerlCal allows remote attackers to read arbitrary files via a .. (dot dot) in the p0 parameter.
https://exchange.xforce.ibmcloud.com/vulnerabilities/6480
http://www.perlcal.com/calendar/docs/bugs.txt
http://archives.neohapsis.com/archives/bugtraq/2001-04/0506.html