USN-4150-1: Thunderbird vulnerabilities thunderbird vulnerabilities A security issue affects these releases of Ubuntu and its derivatives: Ubuntu 19.04 Ubuntu 18.04 LTS Ubuntu 16.04 LTS Summary Several security issues were fixed in Thunderbird. Software Description thunderbird – Mozilla Open Source mail and newsgroup client Details It was discovered that encrypted S/MIME parts in a multipart message can leak plaintext contents when included in a HTML reply or forward in some circumstances. If a user were tricked in to replying to or forwarding a specially crafted message, an attacker could potentially exploit this to obtain sensitive information. (CVE-2019-11739) 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 obtain sensitive information, conduct cross-site scripting (XSS) attack, scause a denial of service, or [ more… ]