Hastymail 1.0.1 and earlier (stable) and 1.1 and earlier (development) does not send the "attachment" parameter in the Content-Disposition field for attachments, which causes the attachment to be rendered inline by Internet Explorer when the victim clicks the download link, which facilitates cross-site scripting (XSS) and possibly other attacks.

Hastymail2 before RC 8 does not set the secure flag for the session cookie in an https session, which makes it easier for remote attackers to capture this cookie by intercepting its transmission within an http session.

Cross-site scripting (XSS) vulnerability in Hastymail2 before 1.01 allows remote attackers to inject arbitrary web script or HTML via a crafted background attribute within a cell in a TABLE element, related to improper use of the htmLawed filter.

Cross-site scripting (XSS) vulnerability in index.php in Hastymail2 2.1.1 before RC2 allows remote attackers to inject arbitrary web script or HTML via the rs parameter in a mailbox Drafts action.

Hastymail2 2.1.1 before RC2 allows remote attackers to execute arbitrary commands via the (1) rs or (2) rsargs[] parameter in a mailbox Drafts action to the default URI.