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Fencer Intel
critical 9.8

CVE-2019-9791 in the critical feed json

The type inference system allows the compilation of functions that can cause type confusions between arbitrary objects when compiled throug…

published 7y ago modified 4mo ago also EUVD-2019-19153

cvss
9.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
19.9%
EPSS 19.9% chance of exploitation in 30 days, percentile 97%
public exploits
1
Exploit-DB

Summary

The type inference system allows the compilation of functions that can cause type confusions between arbitrary objects when compiled through the IonMonkey just-in-time (JIT) compiler and when the constructor function is entered through on-stack replacement (OSR). This allows for possible arbitrary reading and writing of objects during an exploitable crash. This vulnerability affects Thunderbird < 60.6, Firefox ESR < 60.6, and Firefox < 66.

Patch / fix

  • Mozilla Thunderbird 60.6
  • Mozilla Firefox ESR 60.6
  • Mozilla Firefox 66
  • firefox-esr Debian 14, Debian 13, Debian 12 60.6.0esr-1
  • thunderbird Debian 14, Debian 13, Debian 12 1:60.6.1-1

debian advisories DEBIAN-CVE-2019-9791

  • firefox Ubuntu 14.04 LTS 66.0.1+build1-0ubuntu0.14.04.1
  • firefox Ubuntu 16.04 LTS 66.0+build3-0ubuntu0.16.04.2
  • firefox Ubuntu 18.04 LTS 66.0+build3-0ubuntu0.18.04.1
  • thunderbird Ubuntu 14.04 LTS 1:60.6.1+build2-0ubuntu0.14.04.1
  • thunderbird Ubuntu 16.04 LTS 1:60.6.1+build2-0ubuntu0.16.04.1
  • thunderbird Ubuntu 18.04 LTS 1:60.6.1+build2-0ubuntu0.18.04.1

ubuntu advisories UBUNTU-CVE-2019-9791

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 60.6.1-1.el8
  • thunderbird RHEL 7 60.6.1-1.el7_6
  • firefox RHEL 8 60.6.1-1.el8
  • thunderbird RHEL 6 60.6.1-1.el6_10
  • firefox RHEL 6 60.6.0-3.el6_10
  • firefox RHEL 7 60.6.0-3.el7_6

red hat advisories RHSA-2019:1144RHSA-2019:0681RHSA-2019:0966RHSA-2019:0680RHSA-2019:0623RHSA-2019:0622

  • MozillaFirefox SLE Module for Desktop Applications 15 60.6.1-3.29.3
  • MozillaThunderbird SLE Workstation Extension 15 60.6.1-3.28.1
  • MozillaFirefox SLES for SAP 12 SP4, SLES for SAP 12 SP3, SLES for SAP 12 SP2 +13 more 60.6.1esr-109.63.2

suse advisories SUSE-SU-2019:0871-1SUSE-SU-2019:0853-1SUSE-SU-2019:0852-1

  • firefox-esr openSUSE Tumbleweed 128.5.1-1.1
  • MozillaFirefox openSUSE Tumbleweed 92.0-1.2
  • MozillaThunderbird openSUSE Leap 15.0 60.6.1-lp150.3.37.1
  • MozillaThunderbird Package Hub 12 60.6.1-82.1
  • MozillaFirefox openSUSE Leap 15.0 60.6.1-lp150.3.45.1

opensuse advisories openSUSE-SU-2024:14572-1openSUSE-SU-2024:10600-1openSUSE-SU-2019:1162-1openSUSE-SU-2019:1126-1openSUSE-SU-2019:1077-1

  • firefox-esr Alpine 3.23, Alpine 3.22, Alpine 3.21 +12 more 60.6.1-r0

alpine advisories ALPINE-CVE-2019-9791

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 66.0-1

arch linux advisories AVG-925

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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-2019-9791 updated cvss 9.8

Mozilla: Type inference is incorrect for constructors entered through on-stack replacement with IonMonkey

  • Red Hat Enterprise Linux AppStream (v. 8) firefox 60.6.1-1.el8, thunderbird 60.6.1-1.el8
    fixed: vendor fix RHSA-2019:0966
  • Red Hat Enterprise Linux Client (v. 7) firefox 60.6.0-3.el7_6, thunderbird 60.6.1-1.el7_6 Red Hat Enterprise Linux Client Optional (v. 7) firefox 60.6.0-3.el7_6
    fixed: vendor fix RHSA-2019:0622
  • Red Hat Enterprise Linux Desktop (v. 6) firefox 60.6.0-3.el6_10, thunderbird 60.6.1-1.el6_10 Red Hat Enterprise Linux Desktop Optional (v. 6) firefox 60.6.0-3.el6_10
    fixed: vendor fix RHSA-2019:0623
  • Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server (v. 7) firefox 60.6.0-3.el7_6
    fixed: vendor fix RHSA-2019:0622
  • Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server Optional (v. 7) thunderbird 60.6.1-1.el7_6
    fixed: vendor fix RHSA-2019:0681
  • Red Hat Enterprise Linux HPC Node Optional (v. 6) firefox 60.6.0-3.el6_10 Red Hat Enterprise Linux Server (v. 6) firefox 60.6.0-3.el6_10
    fixed: vendor fix RHSA-2019:0623
  • Red Hat Enterprise Linux Server (v. 7) firefox 60.6.0-3.el7_6
    fixed: vendor fix RHSA-2019:0622
  • Red Hat Enterprise Linux Server Optional (v. 6) firefox 60.6.0-3.el6_10, thunderbird 60.6.1-1.el6_10
    fixed: vendor fix RHSA-2019:0623
show 5 more
  • Red Hat Enterprise Linux Server Optional (v. 7) firefox 60.6.0-3.el7_6, thunderbird 60.6.1-1.el7_6
    fixed: vendor fix RHSA-2019:0622
  • Red Hat Enterprise Linux Workstation (v. 6) firefox 60.6.0-3.el6_10, thunderbird 60.6.1-1.el6_10
    fixed: vendor fix RHSA-2019:0623
  • Red Hat Enterprise Linux Workstation (v. 7) firefox 60.6.0-3.el7_6, thunderbird 60.6.1-1.el7_6
    fixed: vendor fix RHSA-2019:0622
  • Red Hat Enterprise Linux Workstation Optional (v. 6) firefox 60.6.0-3.el6_10
    fixed: vendor fix RHSA-2019:0623
  • Red Hat Enterprise Linux Workstation Optional (v. 7) firefox 60.6.0-3.el7_6
    fixed: vendor fix RHSA-2019:0622

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

Timeline

  1. First public exploit (EDB-46613)
  2. Published

Exploit prediction

19.92% chance of exploitation in the next 30 days, higher than 97% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • EDB-46613 Spidermonkey - IonMonkey Type Inference is Incorrect for Constructors Entered via OSR dos, 2019-03-26
  • bugzilla.mozilla.org https://bugzilla.mozilla.org/show_bug.cgi?id=1530958 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P

Affected products

  • Mozilla Thunderbird
  • Mozilla Firefox ESR
  • Mozilla Firefox

Classification

Weakness
  • CWE-843 Access of Resource Using Incompatible Type

References

Sources

Fencer Intel 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.