Several security issues were fixed in Thunderbird.
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, or execute arbitrary code. (CVE-2018-12376, CVE-2018-12377, CVE-2018-12378)
15 October 2018
A security issue affects these releases of Ubuntu and its derivatives:
Several security issues were fixed in Thunderbird.
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, or execute arbitrary code. (CVE-2018-12376, CVE-2018-12377, CVE-2018-12378)
It was discovered that if a user saved passwords before Thunderbird 58 and then later set a master password, an unencrypted copy of these passwords would still be accessible. A local user could exploit this to obtain sensitive information. (CVE-2018-12383)
A crash was discovered in TransportSecurityInfo used for SSL, which could be triggered by data stored in the local cache directory. An attacker could potentially exploit this in combination with another vulnerability that allowed them to write data to the cache, to execute arbitrary code. (CVE-2018-12385)
The problem can be corrected by updating your system to the following package versions:
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
After a standard system update you need to restart Thunderbird to make all the necessary changes.