Type Confusion in Firefox ESR and Mozilla Firefox - CVE-2019-17026

Vulnerability identifier: #VU24147

CSH Severity: Critical

CVSS v4: 8.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2019-17026

CWE-ID: CWE-843

Exploitation vector: Remote access

Exploit availability: The vulnerability is being exploited in the wild

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to a type confusion error with StoreElementHole and FallibleStoreElement when processing HTML content in IonMonkey JIT compiler. A remote attacker can create a specially crafted webpage, trick the victim into visiting it, trigger a type confusion error and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Note, this vulnerability is being actively exploited in the wild.

Firefox ESR
Mozilla Firefox
Gentoo Linux
Arch Linux
Red Hat Enterprise Linux Server
Red Hat Enterprise Linux for Scientific Computing
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux Desktop
Red Hat Enterprise Linux Workstation
Red Hat Enterprise Linux for x86_64
Slackware Linux
Opensuse
Red Hat Enterprise Linux Server for x86_64 - Update Services for SAP Solutions
firefox (Ubuntu package)
thunderbird (Debian package)
thunderbird (Ubuntu package)
firefox-esr (Alpine package)
firefox (Alpine package)
firefox-esr (Debian package)
Mozilla Thunderbird

Update to Firefox 72.0.1 or Firefox ESR 68.4.1.

Firefox ESR - update to 68.4.1
Mozilla Firefox - update to 72.0.1
firefox (Ubuntu package) - addressed in versions 72.0.1+build1-0ubuntu0.16.04.1, 72.0.1+build1-0ubuntu0.18.04.1, 72.0.1+build1-0ubuntu0.19.04.1, 72.0.1+build1-0ubuntu0.19.10.1
thunderbird (Debian package) - addressed in versions 1:68.4.1-1~deb9u1, 1:68.4.1-1~deb10u1
thunderbird (Ubuntu package) - addressed in versions 1:68.4.1+build1-0ubuntu0.18.04.1, 1:68.4.1+build1-0ubuntu0.19.10.1, 1:68.7.0+build1-0ubuntu0.16.04.2
Mozilla Thunderbird - update to 68.4.1
firefox-esr (Alpine package) - update to 68.4.1-r0
firefox (Alpine package) - update to 72.0.1-r0
firefox-esr (Debian package) - update to 68.4.1esr-1~deb10u1

• Exploit #7817 - Mozilla Firefox 67 - Array.pop JIT Type Confusion (May 13, 2022)
• Exploit #5455 - Firefox 72 IonMonkey - JIT Type Confusion (May 20, 2021)
• Exploit #4537 - CVE-2019-17026-Exploit (An exploit for CVE-2019-17026. It pops xcalc and was tested on Ubuntu (x64).) (September 1, 2020)

• https://www.mozilla.org/en-US/security/advisories/mfsa2020-03/

• Remote code execution in Mozilla Firefox and Firefox ESR
• Slackware Linux update for mozilla-firefox
• Debian update for firefox-esr
• Ubuntu update for Firefox
• Arch Linux update for firefox
• Slackware Linux update for mozilla-thunderbird
• Multiple vulnerabilities in Mozilla Thunderbird
• Red Hat update for firefox
• Red Hat update for firefox
• Arch Linux update for thunderbird
• Red Hat update for firefox
• OpenSUSE Linux update for MozillaFirefox
• Red Hat update for thunderbird
• Red Hat update for thunderbird
• Red Hat update for thunderbird
• Ubuntu update for Thunderbird
• Debian update for thunderbird
• OpenSUSE Linux update for MozillaThunderbird
• Red Hat update for firefox
• Red Hat update for thunderbird
• Gentoo update for Mozilla Firefox
• Ubuntu update for Thunderbird
• Type Confusion in firefox (Alpine package)
• Type Confusion in firefox-esr (Alpine package)