Christopher Bohn

Thunderbird on Linux and Windows contains a flaw where specially crafted link attachments, such as `.desktop` files on Linux or `.url` and `.lnk` files on Windows, are replaced with the actual content of the file or URL they point to. This occurs when a message is forwarded inline, edited as new, or when an attachment is dragged into a compose window and subsequently saved or sent. This behavior can lead to the disclosure of local files or content from the user's network to the mail provider or the message recipients.

When a CalDAV or ICS calendar was accessed through an HTTP proxy that requested authentication, Thunderbird could answer the proxy with the calendar server's username and password. This affected both setting up a new calendar and syncing existing calendars, where a saved password could be sent without any user interaction. A malicious or compromised proxy could use this to obtain the calendar credentials, even for calendars served over HTTPS. This vulnerability was fixed in Thunderbird 160 and Thunderbird 153.7.

The issue allows remote attackers to cause a denial of service, resulting in a system panic, by sending crafted IGMP packets. This is due to incorrect, extraneous code in the IGMP parser.