CVE 2012-0796

class.phpmailer.php in the PHPMailer library, as used in Moodle 1.9.x before 1.9.16, 2.0.x before 2.0.7, 2.1.x before 2.1.4, and 2.2.x before 2.2.1 and other products, allows remote authenticated users to inject arbitrary e-mail headers via vectors involving a crafted (1) From: or (2) Sender: header.

See the CVE page on Mitre.org for more details.