TestLink before 1.7.1 does not enforce an unspecified authorization mechanism, which has unknown impact and attack vectors.
https://euvd.enisa.europa.eu/vulnerability/EUVD-2007-5976
http://www.securityfocus.com/bid/26439
http://sourceforge.net/project/shownotes.php?release_id=548619&group_id=90976