CVE-2020-12398

Si Thunderbird está configurado para usar STARTTLS para un servidor IMAP, y el servidor envía una respuesta PREAUTH, entonces Thunderbird continuará con una conexión sin cifrar, causando que unos datos de correo electrónico sean enviados sin protección. Esta vulnerabilidad afecta a Thunderbird versiones anteriores a 68.9.0

The Mozilla Foundation Security Advisory describes this flaw as: If Thunderbird is configured to use STARTTLS for an IMAP server, and the server sends a PREAUTH response, then Thunderbird will continue with an unencrypted connection, causing email data to be sent without protection.

Multiple security issues were discovered in Thunderbird. If a user were tricked in to opening a specially crafted website in a browsing context, an attacker could potentially exploit these to cause a denial of service, obtain sensitive information, or execute arbitrary code. It was discovered that Thunderbird would continue an unencrypted connection when configured to use STARTTLS for IMAP if the server responded with PREAUTH. A remote attacker could potentially exploit this to perform a person-in-the-middle attack in order to obtain sensitive information. Various other issues were also addressed.