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Fencer Vulns
high 8.8

CVE-2020-35112 json

If a user downloaded a file lacking an extension on Windows, and then "Open"-ed it from the downloads panel, if there was an executable fil…

published 2021-01-07 5 y ago modified 2026-06-17 4 mo ago also EUVD-2020-22808

cvss
8.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.3%
EPSS 1.3% chance of exploitation in 30 days, percentile 70%
public exploits
0
none known

Summary

If a user downloaded a file lacking an extension on Windows, and then "Open"-ed it from the downloads panel, if there was an executable file in the downloads directory with the same name but with an executable extension (such as .bat or .exe) that executable would have been launched instead. *Note: This issue only affected Windows operating systems. Other operating systems are unaffected.*. This vulnerability affects Firefox < 84, Thunderbird < 78.6, and Firefox ESR < 78.6.

Patch / fix

  • Mozilla Firefox 84
  • Mozilla Thunderbird 78.6
  • Mozilla Firefox ESR 78.6
  • MozillaThunderbird SLE Workstation Extension 15 SP2 78.6.0-8.3.1
  • MozillaFirefox SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +15 more 78.6.0-112.39.1
  • MozillaFirefox SLE Module for Desktop Applications 15 SP1 78.6.0-3.122.1
  • MozillaFirefox SLE Module for Desktop Applications 15 SP2 78.6.0-8.20.2
  • MozillaThunderbird SLE Workstation Extension 15 SP1 78.6.0-3.113.1
  • MozillaFirefox SLES 11 SP4-LTSS 78.6.0-78.108.1

suse advisories SUSE-SU-2020:3935-1SUSE-SU-2020:3903-1SUSE-SU-2020:3902-1SUSE-SU-2020:3901-1SUSE-SU-2020:3900-1SUSE-SU-2020:14584-1

  • firefox-esr openSUSE Tumbleweed 128.5.1-1.1
  • MozillaFirefox openSUSE Tumbleweed 92.0-1.2
  • MozillaThunderbird openSUSE Tumbleweed 91.1.1-1.1
  • MozillaFirefox openSUSE Leap 15.1 78.6.0-lp151.2.82.1
  • MozillaThunderbird openSUSE Leap 15.1 78.6.0-lp151.2.63.1
  • MozillaFirefox openSUSE Leap 15.2 78.6.0-lp152.2.34.1
  • MozillaThunderbird openSUSE Leap 15.2 78.6.0-lp152.2.23.1

opensuse advisories openSUSE-SU-2024:14572-1openSUSE-SU-2024:10600-1openSUSE-SU-2024:10601-1openSUSE-SU-2020:2325-1openSUSE-SU-2020:2324-1openSUSE-SU-2020:2318-1

  • firefox Alpine 3.23, Alpine 3.22, Alpine 3.21 +9 more 84.0.1-r0
  • librewolf Alpine 3.24, Alpine 3.23, Alpine 3.22 +1 more 84.0.1-r0
  • firefox-esr Alpine 3.23, Alpine 3.22, Alpine 3.21 +9 more 78.6.0-r0
  • thunderbird Alpine 3.23, Alpine 3.22, Alpine 3.21 +5 more 78.6.1-r0

alpine advisories ALPINE-CVE-2020-35112

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

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-2020-35112 updated cvss 8.8

Mozilla: Opening an extension-less download may have inadvertently launched an executable instead

  • Red Hat Enterprise Linux 5 thunderbird Red Hat Enterprise Linux 6 firefox, thunderbird Red Hat Enterprise Linux 7 firefox, thunderbird Red Hat Enterprise Linux 8 firefox, thunderbird
    not affected: vulnerable code not present

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

1.27% chance of exploitation in the next 30 days, higher than 70% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD 2.0 6.8 AV:N/AC:M/Au:N/C:P/I:P/A:P

Affected products

  • Mozilla Firefox
  • Mozilla Thunderbird
  • Mozilla Firefox ESR

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.