Cleartext transmission of sensitive information in Mozilla Thunderbird - CVE-2020-12398

Vulnerability identifier: #VU28569

CSH Severity: Medium

CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2020-12398

CWE-ID: CWE-319

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to gain access to sensitive information.

The vulnerability exists in STARTTLS implementation for an IMAP, when the server sends  a PREAUTH response. In this case Thunderbird will continue with an unencrypted connection, causing email data to be sent without protection.

Mozilla Thunderbird
Arch Linux
Gentoo Linux
Red Hat Enterprise Linux Server
Red Hat Enterprise Linux for Power, big endian
Red Hat Enterprise Linux Workstation
Red Hat Enterprise Linux Desktop
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux for x86_64 - Extended Update Support
Red Hat Enterprise Linux for Power, little endian - Extended Update Support
Red Hat Enterprise Linux Server - TUS
Oracle Solaris
Slackware Linux
Opensuse
Ubuntu
Red Hat Enterprise Linux Server for x86_64 - Update Services for SAP Solutions
Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions
thunderbird (Debian package)
thunderbird (Red Hat package)
thunderbird (Alpine package)
thunderbird (Ubuntu package)

Install updates from vendor's website.

Mozilla Thunderbird - update to 68.9.0
thunderbird (Debian package) - addressed in versions 1:68.9.0-1~deb9u1, 1:68.9.0-1~deb10u1
thunderbird (Red Hat package) - addressed in versions 68.9.0-1.el6_10, 68.9.0-1.el7_8, 68.9.0-1.el8_0, 68.9.0-1.el8_1, 68.9.0-1.el8_2
thunderbird (Alpine package) - update to 68.9.0-r0
thunderbird (Ubuntu package) - addressed in versions 1:68.10.0+build1-0ubuntu0.16.04.1, 1:68.10.0+build1-0ubuntu0.18.04.1, 1:68.10.0+build1-0ubuntu0.19.10.1, 1:68.10.0+build1-0ubuntu0.20.04.1

• https://www.mozilla.org/en-US/security/advisories/mfsa2020-22/
• https://bugzilla.mozilla.org/show_bug.cgi?id=1613623

• Multiple vulnerabilities in Mozilla Thunderbird
• Slackware Linux update for mozilla-thunderbird
• Arch Linux update for thunderbird
• OpenSUSE Linux update for MozillaThunderbird
• Debian update for thunderbird
• Gentoo update for Mozilla Thunderbird
• Red Hat Enterprise Linux 6 update for thunderbird
• Red Hat Enterprise Linux 8 update for thunderbird
• Red Hat Enterprise Linux 7 update for thunderbird
• Red Hat Enterprise Linux 8 update for thunderbird
• Oracle Solaris security update for third party software (July 2020)
• Cleartext transmission of sensitive information in thunderbird (Alpine package)
• Red Hat Enterprise Linux 8.1 Extended Update Support update for thunderbird
• Ubuntu update for thunderbird