The Mobile Edition of TransWARE Active! mail 2003 build 2003.0139.0871 and earlier, and possibly other versions before 2003.0139.0911, does not remove the session ID in a Referer URL, which allows remote attackers to hijack web sessions via vectors such as an email with an embedded URL.
https://exchange.xforce.ibmcloud.com/vulnerabilities/54751
http://www.transware.co.jp/support_am/security/vulnerability3.html
http://secunia.com/advisories/37602