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Fencer Vulns
medium 6.5

CVE-2020-6794 json

If a user saved passwords before Thunderbird 60 and then later set a master password, an unencrypted copy of these passwords is still acces…

published 2020-03-02 6 y ago modified 2026-06-17 4 mo ago also EUVD-2020-27941

cvss
6.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.0%
EPSS 1.0% chance of exploitation in 30 days, percentile 63%
public exploits
0
none known

Summary

If a user saved passwords before Thunderbird 60 and then later set a master password, an unencrypted copy of these passwords is still accessible. This is because the older stored password file was not deleted when the data was copied to a new format starting in Thunderbird 60. The new master password is added only on the new file. This could allow the exposure of stored password data outside of user expectations. This vulnerability affects Thunderbird < 68.5.

Patch / fix

  • Mozilla Thunderbird 68.5
  • thunderbird Debian 14, Debian 13, Debian 12 1:68.5.0-1

debian advisories DEBIAN-CVE-2020-6794

  • thunderbird Ubuntu 16.04 LTS 1:68.7.0+build1-0ubuntu0.16.04.2
  • thunderbird Ubuntu 18.04 LTS 1:68.7.0+build1-0ubuntu0.18.04.1

ubuntu advisories UBUNTU-CVE-2020-6794

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • thunderbird RHEL 7 68.5.0-1.el7_7
  • thunderbird RHEL 6 68.5.0-1.el6_10
  • thunderbird RHEL 8 68.5.0-1.el8_1
  • thunderbird RHEL 8.0 E4S 68.5.0-1.el8_0

red hat advisories RHSA-2020:0576RHSA-2020:0574RHSA-2020:0577RHSA-2020:0565

  • MozillaThunderbird SLE Workstation Extension 15 SP1 68.5.0-3.71.1

suse advisories SUSE-SU-2020:0385-1

  • MozillaThunderbird openSUSE Tumbleweed 91.1.1-1.1
  • MozillaThunderbird openSUSE Leap 15.1 68.5.0-lp151.2.25.1

opensuse advisories openSUSE-SU-2024:10601-1openSUSE-SU-2020:0231-1

  • thunderbird Alpine 3.23, Alpine 3.22, Alpine 3.21 +5 more 68.5.0-r0

alpine advisories ALPINE-CVE-2020-6794

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • thunderbird Arch Linux 68.5.0-1

arch linux advisories AVG-1099

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2020-6794 updated cvss 6.1

Mozilla: Setting a master password post-Thunderbird 52 does not delete unencrypted previously stored passwords

  • Red Hat Enterprise Linux 5 thunderbird
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux AppStream (v. 8) thunderbird 68.5.0-1.el8_1
    fixed: vendor fix RHSA-2020:0577
  • Red Hat Enterprise Linux AppStream E4S (v. 8.0) thunderbird 68.5.0-1.el8_0
    fixed: vendor fix RHSA-2020:0565
  • Red Hat Enterprise Linux Client (v. 7) thunderbird 68.5.0-1.el7_7
    fixed: vendor fix RHSA-2020:0576
  • Red Hat Enterprise Linux Desktop (v. 6) thunderbird 68.5.0-1.el6_10 Red Hat Enterprise Linux Server Optional (v. 6) thunderbird 68.5.0-1.el6_10
    fixed: vendor fix RHSA-2020:0574
  • Red Hat Enterprise Linux Server Optional (v. 7) thunderbird 68.5.0-1.el7_7
    fixed: vendor fix RHSA-2020:0576
  • Red Hat Enterprise Linux Workstation (v. 6) thunderbird 68.5.0-1.el6_10
    fixed: vendor fix RHSA-2020:0574
  • Red Hat Enterprise Linux Workstation (v. 7) thunderbird 68.5.0-1.el7_7
    fixed: vendor fix RHSA-2020:0576

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.02% chance of exploitation in the next 30 days, higher than 63% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • bugzilla.mozilla.org https://bugzilla.mozilla.org/show_bug.cgi?id=1606619 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:P/I:N/A:N

Affected products

  • Mozilla Thunderbird

Classification

Weakness
  • CWE-312 Cleartext Storage of Sensitive Information
  • CWE-459 Incomplete Cleanup
  • CWE-522 Insufficiently Protected Credentials

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.