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Fencer Vulns
critical 9.3

CVE-2019-9812 json

Given a compromised sandboxed content process due to a separate vulnerability, it is possible to escape that sandbox by loading accounts.fi…

published 2020-01-08 6 y ago modified 2026-06-17 4 mo ago also EUVD-2019-19174

cvss
9.3
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.5%
EPSS 1.5% chance of exploitation in 30 days, percentile 74%
public exploits
0
none known

Summary

Given a compromised sandboxed content process due to a separate vulnerability, it is possible to escape that sandbox by loading accounts.firefox.com in that process and forcing a log-in to a malicious Firefox Sync account. Preference settings that disable the sandbox are then synchronized to the local machine and the compromised browser would restart without the sandbox if a crash is triggered. This vulnerability affects Firefox ESR < 60.9, Firefox ESR < 68.1, and Firefox < 69.

Patch / fix

  • mozilla firefox 60.9, 68.1, 69.0
  • firefox-esr Debian 14, Debian 13, Debian 12 68.1.0esr-1

debian advisories DEBIAN-CVE-2019-9812

  • firefox Ubuntu 16.04 LTS 69.0+build2-0ubuntu0.16.04.4
  • firefox Ubuntu 18.04 LTS 69.0+build2-0ubuntu0.18.04.1

ubuntu advisories UBUNTU-CVE-2019-9812

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

  • firefox RHEL 7 60.9.0-1.el7_7
  • firefox RHEL 6 60.9.0-1.el6_10
  • firefox RHEL 8 68.1.0-1.el8_0

red hat advisories RHSA-2019:2729RHSA-2019:2694RHSA-2019:2663

  • MozillaFirefox SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +18 more 68.1.0-109.89.1
  • MozillaFirefox-branding-SLE SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +16 more 68-32.8.1
  • MozillaFirefox SLE Module for Desktop Applications 15 SP1, SLE Module for Desktop Applications 15 68.1.0-3.54.2
  • MozillaFirefox-branding-SLE SLE Module for Desktop Applications 15 SP1, SLE Module for Desktop Applications 15 68-4.8.5
  • MozillaFirefox SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +18 more 60.9.0-109.86.1
  • firefox-atk SLES 11 SP4-LTSS 2.26.1-2.8.4
  • mozilla-nss SLES 11 SP4-LTSS 3.45-38.9.3
  • firefox-gtk3 SLES 11 SP4-LTSS 3.10.9-2.15.3

suse advisories SUSE-SU-2019:14246-1SUSE-SU-2019:2620-1SUSE-SU-2019:2545-1SUSE-SU-2019:2436-1SUSE-SU-2019:14173-1

  • firefox-esr openSUSE Tumbleweed 128.5.1-1.1
  • MozillaFirefox openSUSE Tumbleweed 92.0-1.2
  • MozillaFirefox openSUSE Leap 15.0 68.1.0-lp150.3.66.1
  • MozillaFirefox openSUSE Leap 15.1 68.1.0-lp151.2.14.1

opensuse advisories openSUSE-SU-2024:14572-1openSUSE-SU-2024:10600-1openSUSE-SU-2019:2260-1openSUSE-SU-2019:2251-1

  • firefox-esr Alpine 3.10, Alpine 3.9 69.9.0-r0
  • firefox-esr Alpine 3.23, Alpine 3.22, Alpine 3.21 +10 more 68.1.0-r0

alpine advisories ALPINE-CVE-2019-9812

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 69.0-1

arch linux advisories AVG-1036

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-2019-9812 updated cvss 9.3

Mozilla: Sandbox escape through Firefox Sync

  • Red Hat Enterprise Linux 5 firefox
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux AppStream (v. 8) firefox 68.1.0-1.el8_0
    fixed: vendor fix RHSA-2019:2663
  • Red Hat Enterprise Linux Client (v. 7) firefox 60.9.0-1.el7_7 Red Hat Enterprise Linux Client Optional (v. 7) firefox 60.9.0-1.el7_7
    fixed: vendor fix RHSA-2019:2729
  • Red Hat Enterprise Linux Desktop (v. 6) firefox 60.9.0-1.el6_10 Red Hat Enterprise Linux Desktop Optional (v. 6) firefox 60.9.0-1.el6_10 Red Hat Enterprise Linux HPC Node Optional (v. 6) firefox 60.9.0-1.el6_10 Red Hat Enterprise Linux Server (v. 6) firefox 60.9.0-1.el6_10
    fixed: vendor fix RHSA-2019:2694
  • Red Hat Enterprise Linux Server (v. 7) firefox 60.9.0-1.el7_7
    fixed: vendor fix RHSA-2019:2729
  • Red Hat Enterprise Linux Server Optional (v. 6) firefox 60.9.0-1.el6_10
    fixed: vendor fix RHSA-2019:2694
  • Red Hat Enterprise Linux Server Optional (v. 7) firefox 60.9.0-1.el7_7
    fixed: vendor fix RHSA-2019:2729
  • Red Hat Enterprise Linux Workstation (v. 6) firefox 60.9.0-1.el6_10
    fixed: vendor fix RHSA-2019:2694
show 3 more
  • Red Hat Enterprise Linux Workstation (v. 7) firefox 60.9.0-1.el7_7
    fixed: vendor fix RHSA-2019:2729
  • Red Hat Enterprise Linux Workstation Optional (v. 6) firefox 60.9.0-1.el6_10
    fixed: vendor fix RHSA-2019:2694
  • Red Hat Enterprise Linux Workstation Optional (v. 7) firefox 60.9.0-1.el7_7
    fixed: vendor fix RHSA-2019:2729

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

1.51% chance of exploitation in the next 30 days, higher than 74% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 9.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:H/A:H
NVD 2.0 5.8 AV:N/AC:M/Au:N/C:N/I:P/A:P

Affected products

  • Mozilla Firefox ESR
  • Mozilla Firefox

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.