CVE-2008-4103
The mailto (aka com_mailto) component in Joomla! 1.5 before 1.5.7 sends e-mail messages without validating the URL, which allows remote attackers to transmit spam.
Date published : 2008-09-18
http://developer.joomla.org/security/news/273-20080903-core-commailto-spam.html