source: https://www.securityfocus.com/bid/11767/info

pnTresMailer is reported susceptible to a directory traversal vulnerability. This issue is due to a failure of the application to properly sanitize user-supplied input data.

This vulnerability can be exploited to retrieve arbitrary, potentially sensitive files from the hosting computer with the privileges of the web server. This may aid a malicious user in further attacks.

Version 6.03 of the application is reportedly affected by this vulnerability.

http://www.example.com/codebrowserpntm.php?downloadfolder=pnTresMailer&filetodownload=../../../../etc/passwd