Security vulnerabilities fixed in Thunderbird 60.5 — Mozilla

A use-after-free vulnerability can occur while parsing an HTML5 stream in concert with custom HTML elements. This results in the stream parser object being freed while still in use, leading to a potentially exploitable crash.
An earlier fix for an Inter-process Communication (IPC) vulnerability, CVE-2011-3079, added authentication to communication between IPC endpoints and server parents during IPC process creation. This authentication is insufficient for channels created after the IPC process is started, leading to the authentication not being correctly applied to later channels. This could allow for a sandbox escape through IPC channels due to lack of message validation in the listener process.
A use-after-free vulnerability can occur while playing a sound notification in Thunderbird. The memory storing the sound data is immediately freed, although the sound is still being played asynchronously, leading to a potentially exploitable crash.
A vulnerability in the Libical libary used by Thunderbird can allow remote attackers to cause a denial of service (use-after-free) via a crafted ICS calendar file.
A crash can occur when processing a crafted S/MIME message or an XPI package containing a crafted signature. This can be used as a denial-of-service (DOS) attack because Thunderbird reopens the last seen message on restart, triggering the crash again.
Mozilla developers and community members Alex Gaynor, Christoph Diehl, Steven Crane, Jason Kratzer, Gary Kwong, and Christian Holler reported memory safety bugs present in Firefox 64, Firefox ESR 60.4, and Thunderbird 60.4. Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code.