GUI display truncation vulnerability in Mozilla Thunderbird 1.0.2, 1.0.6, and 1.0.7 allows user-assisted attackers to execute arbitrary code via an attachment with a filename containing a large number of spaces ending with a dangerous extension that is not displayed by Thunderbird, along with an inconsistent Content-Type header, which could be used to trick a user into downloading dangerous content by dragging or saving the attachment.
The SMTP client in Mozilla Thunderbird 1.0.5 BETA, 1.0.7, and possibly other versions, does not notify users when it cannot establish a secure channel with the server, which allows remote attackers to obtain authentication information without detection via a man-in-the-middle (MITM) attack that bypasses TLS authentication or downgrades CRAM-MD5 authentication to plain authentication.