Moodle through 2.1.10, 2.2.x before 2.2.10, 2.3.x before 2.3.7, and 2.4.x before 2.4.4 does not consider "don't send" attributes during hub registration, which allows remote hubs to obtain sensitive site information by reading form data.
https://moodle.org/mod/forum/discuss.php?d=228933
http://openwall.com/lists/oss-security/2013/05/21/1
http://lists.fedoraproject.org/pipermail/package-announce/2013-May/107026.html
http://lists.fedoraproject.org/pipermail/package-announce/2013-May/106988.html
http://lists.fedoraproject.org/pipermail/package-announce/2013-May/106965.html
http://git.moodle.org/gw?p=moodle.git&a=search&h=HEAD&st=commit&s=MDL-37822