The start function in class.t3lib_formmail.php in TYPO3 before 4.0.5, 4.1beta, and 4.1RC1 allows attackers to inject arbitrary email headers via unknown vectors. NOTE: some details were obtained from third party information.
https://exchange.xforce.ibmcloud.com/vulnerabilities/32630
http://www.vupen.com/english/advisories/2007/0697
http://www.securityfocus.com/bid/22668
http://typo3.org/teams/security/security-bulletins/typo3-20070221-1