Text_Filter/lib/Horde/Text/Filter/Xss.php in Horde Application Framework before 3.3.6, Horde Groupware before 1.2.5, and Horde Groupware Webmail Edition before 1.2.5 does not properly handle data: URIs, which allows remote attackers to conduct cross-site scripting (XSS) attacks via data:text/html values for the HREF attribute of an A element in an HTML e-mail message. NOTE: the vendor states that the issue is caused by “an XSS vulnerability in Firefox browsers.”
bugs.horde.org/ticket/8715
bugs.horde.org/view.php?actionID=view_file&type=patch&file=0002-Bug-8715-Fix-XSS-vulnerability%5B1%5D.patch&ticket=8715
cvs.horde.org/diff.php/horde/docs/CHANGES?r1=1.515.2.559&r2=1.515.2.589&ty=h
lists.horde.org/archives/announce/2009/000529.html
marc.info/?l=horde-announce&m=126100750018478&w=2
marc.info/?l=horde-announce&m=126101076422179&w=2
securitytracker.com/id?1023365