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Fencer Vulns
medium 6.5

CVE-2022-31742 json

An attacker could have exploited a timing attack by sending a large number of allowCredential entries and detecting the difference between…

published 2022-12-22 3 y ago modified 2026-06-17 4 mo ago also EUVD-2022-53140

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 50%
public exploits
0
none known

Summary

An attacker could have exploited a timing attack by sending a large number of allowCredential entries and detecting the difference between invalid key handles and cross-origin key handles. This could have led to cross-origin account linking in violation of WebAuthn goals. This vulnerability affects Thunderbird < 91.10, Firefox < 101, and Firefox ESR < 91.10.

Patch / fix

  • Mozilla Thunderbird 91.10
  • Mozilla Firefox 101
  • Mozilla Firefox ESR 91.10
  • firefox-esr Debian 14, Debian 13, Debian 12 91.10.0esr-1
  • thunderbird Debian 14, Debian 13, Debian 12 1:91.10.0-1

debian advisories DEBIAN-CVE-2022-31742

  • firefox Ubuntu 18.04 LTS 101.0.1+build1-0ubuntu0.18.04.1
  • firefox Ubuntu 20.04 LTS 101.0.1+build1-0ubuntu0.20.04.1
  • thunderbird Ubuntu 18.04 LTS 1:91.11.0+build2-0ubuntu0.18.04.1
  • thunderbird Ubuntu 20.04 LTS 1:91.11.0+build2-0ubuntu0.20.04.1
  • thunderbird Ubuntu 22.04 LTS 1:91.11.0+build2-0ubuntu0.22.04.1

ubuntu advisories UBUNTU-CVE-2022-31742

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 8 91.10.0-1.el8_6
  • thunderbird RHEL 9 91.10.0-1.el9_0
  • firefox RHEL 7 91.10.0-1.el7_9
  • thunderbird RHEL 7 91.10.0-1.el7_9
  • firefox RHEL 8 91.10.0-1.el8_6
  • firefox RHEL 9 91.10.0-1.el9_0
  • thunderbird RHEL 8.2 EUS 91.10.0-1.el8_2
  • thunderbird RHEL 8.1 E4S 91.10.0-1.el8_1

red hat advisories RHSA-2022:4890RHSA-2022:4888RHSA-2022:4887RHSA-2022:4889RHSA-2022:4871RHSA-2022:4892

  • MozillaThunderbird SLE Workstation Extension 15 SP4, SLE Workstation Extension 15 SP3, SLE Module for Package Hub 15 SP4 +3 more 91.10.0-150200.8.73.1
  • MozillaFirefox SLES for SAP 15 SP1, SLES for SAP 15, SLES 15-LTSS +7 more 91.10.0-150000.150.44.1
  • MozillaFirefox SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +11 more 91.10.0-112.114.1
  • MozillaFirefox SLES for SAP 15 SP2, SLES 15 SP2-LTSS, SLES 15 SP2-BCL +10 more 91.10.0-150200.152.43.1

suse advisories SUSE-SU-2022:2062-1SUSE-SU-2022:1927-1SUSE-SU-2022:1921-1SUSE-SU-2022:1920-1

  • firefox-esr openSUSE Tumbleweed 128.5.1-1.1
  • MozillaThunderbird openSUSE Tumbleweed 91.10.0-1.1
  • MozillaFirefox openSUSE Tumbleweed 101.0-1.1

opensuse advisories openSUSE-SU-2024:14572-1openSUSE-SU-2024:12117-1openSUSE-SU-2024:12121-1

  • thunderbird Rocky Linux 8 91.10.0-1.el8_6
  • firefox Rocky Linux 8 91.10.0-1.el8_6

rocky linux advisories RLSA-2022:4887RLSA-2022:4872

  • firefox Alpine 3.23, Alpine 3.22, Alpine 3.21 +5 more 101.0-r0
  • librewolf Alpine 3.24, Alpine 3.23, Alpine 3.22 +1 more 101.0-r0
  • firefox-esr Alpine 3.23, Alpine 3.22, Alpine 3.21 +6 more 91.10.0-r0
  • thunderbird Alpine 3.23, Alpine 3.22, Alpine 3.21 +5 more 91.10.0-r0

alpine advisories ALPINE-CVE-2022-31742

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

  • firefox Arch Linux 101.0-1
  • thunderbird Arch Linux 91.10-1

arch linux advisories AVG-2760AVG-2761

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-2022-31742 updated cvss 6.1

Mozilla: Querying a WebAuthn token with a large number of allowCredential entries may have leaked cross-origin information

  • Red Hat Enterprise Linux 6 firefox, thunderbird
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux AppStream (v. 8) firefox 91.10.0-1.el8_6, thunderbird 91.10.0-1.el8_6
    fixed: vendor fix RHSA-2022:4872
  • Red Hat Enterprise Linux AppStream (v. 9) firefox 91.10.0-1.el9_0, thunderbird 91.10.0-1.el9_0
    fixed: vendor fix RHSA-2022:4873
  • Red Hat Enterprise Linux AppStream E4S (v. 8.1) firefox 91.10.0-1.el8_1, thunderbird 91.10.0-1.el8_1
    fixed: vendor fix RHSA-2022:4871
  • Red Hat Enterprise Linux AppStream EUS (v. 8.2) firefox 91.10.0-1.el8_2, thunderbird 91.10.0-1.el8_2
    fixed: vendor fix RHSA-2022:4876
  • Red Hat Enterprise Linux AppStream EUS (v.8.4) firefox 91.10.0-1.el8_4, thunderbird 91.10.0-1.el8_4
    fixed: vendor fix RHSA-2022:4875
  • Red Hat Enterprise Linux Client (v. 7) firefox 91.10.0-1.el7_9, thunderbird 91.10.0-1.el7_9 Red Hat Enterprise Linux Client Optional (v. 7) firefox 91.10.0-1.el7_9 Red Hat Enterprise Linux Server (v. 7) firefox 91.10.0-1.el7_9 Red Hat Enterprise Linux Server Optional (v. 7) firefox 91.10.0-1.el7_9, thunderbird 91.10.0-1.el7_9 Red Hat Enterprise Linux Workstation (v. 7) firefox 91.10.0-1.el7_9, thunderbird 91.10.0-1.el7_9 Red Hat Enterprise Linux Workstation Optional (v. 7) firefox 91.10.0-1.el7_9
    fixed: vendor fix RHSA-2022:4870

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

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
18 mo ago

Exploit prediction

0.63% chance of exploitation in the next 30 days, higher than 50% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • bugzilla.mozilla.org https://bugzilla.mozilla.org/show_bug.cgi?id=1730434 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CISA ADP 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
NVD 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

Affected products

  • Mozilla Thunderbird
  • Mozilla Firefox
  • Mozilla Firefox ESR

Classification

Weakness

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.