Microsoft Internet Explorer 6 SP2 allows remote attackers to cause a denial of service (infinite loop and application crash) via two embedded files that call each other.

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.

The WebBrowser ActiveX control, or the Internet Explorer HTML rendering engine (MSHTML), as used in Internet Explorer 6, allows remote attackers to execute arbitrary code in the Local Security context by using the showModalDialog method and modifying the location to execute code such as Javascript, as demonstrated using (1) delayed HTTP redirect operations, and an HTTP response with a Location: header containing a "URL:" prepended to a "ms-its" protocol URI, or (2) modifying the location attribute of the window, as exploited by the Download.ject (aka Scob aka Toofer) using the ADODB.Stream object.