Protection mechanism failure in Mozilla Firefox - CVE-2019-11763

Vulnerability identifier: #VU22168

CSH Severity: Low

CVSS v4: 2.1 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2019-11763

CWE-ID: CWE-693

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to perform XSS attacks.

The vulnerability exists due to the way Firefox processes HTML entities. A remote attacker can create a specially crafted web page and make the browser treat HTML comment text  as HTML, which could have led to XSS in a web application.

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

Install updates from vendor's website.

Mozilla Firefox - update to 70.0
firefox (Ubuntu package) - addressed in versions 70.0+build2-0ubuntu0.16.04.1, 70.0+build2-0ubuntu0.18.04.1, 70.0+build2-0ubuntu0.19.04.1, 70.0+build2-0ubuntu0.19.10.1
thunderbird (Ubuntu package) - addressed in versions 1:68.2.1+build1-0ubuntu0.18.04.1, 1:68.2.1+build1-0ubuntu0.19.10.1, 1:68.2.2+build1-0ubuntu0.18.04.1, 1:68.2.2+build1-0ubuntu0.19.10.1, 1:68.7.0+build1-0ubuntu0.16.04.2
thunderbird (Debian package) - addressed in versions 1:68.2.2-1~deb9u1, 1:68.2.2-1~deb10u1
Mozilla Thunderbird - update to 68.2.0
Firefox ESR - update to 68.2.0
firefox-esr (Debian package) - update to 68.2.0esr-1~deb10u1
firefox-esr (Alpine package) - update to 68.2.0-r0

• https://www.mozilla.org/en-US/security/advisories/mfsa2019-34/

• Multiple vulnerabilities in Mozilla Firefox
• Multiple vulnerabilities in Firefox ESR
• Slackware Linux update for mozilla-firefox
• Multiple vulnerabilities in Mozilla Thunderbird
• Ubuntu update for Firefox
• Red Hat update for firefox
• Debian update for firefox-esr
• Arch Linux update for firefox
• Arch Linux update for thunderbird
• Red Hat update for firefox
• Red Hat update for thunderbird
• Red Hat update for thunderbird
• Red Hat update for firefox
• Red Hat update for thunderbird
• OpenSUSE update for Mozilla Thunderbird
• OpenSUSE update for Mozilla Thunderbird
• OpenSUSE Linux update for MozillaFirefox, MozillaFirefox-branding-SLE
• OpenSUSE Linux update for MozillaFirefox, MozillaFirefox-branding-SLE
• Debian update for thunderbird
• Ubuntu update for Thunderbird
• Ubuntu update for Thunderbird
• Gentoo update for Mozilla Thunderbird
• Ubuntu update for Thunderbird
• Protection mechanism failure in firefox (Alpine package)
• Protection mechanism failure in firefox-esr (Alpine package)