CVE-2019-11763

Firefox ESR: Failure to correctly handle null bytes when processing HTML entities resulted in Firefox incorrectly…

CVE-2019-11763 is fixed in 10 products on 2 platforms, first by thunderbird 1:68.2.1+build1-0ubuntu0.18.04.1, released October 22, 2019. It is not reported as exploited. Patch Radar priority: Urgent.

UrgentFixed on 2 platforms
CVSS
6.1
Critical
Exploitation
None reported
No vendor assessment
CISA KEV
Not listed
Not in the Known Exploited Vulnerabilities catalog
EPSS
0.0115
66th percentile

Failure to correctly handle null bytes when processing HTML entities resulted in Firefox incorrectly parsing these entities. This could have led to HTML comment text being treated as HTML which could have led to XSS in a web application under certain conditions. It could have also led to HTML entities being masked from filters - enabling the use of entities to mask the actual characters of interest from filters. This vulnerability affects Firefox < 70, Thunderbird < 68.2, and Firefox ESR < 68.2.

Where it's fixed

ProductFixed inFixReleased
Windows apps
Mozilla Firefox ESR (en-US) 78.0esr Mozilla Firefox ESR (en-US) 78.0esr Jun 25, 2020
Linux
firefox · RHEL 8 0:68.2.0-2.el8_0 RHSA-2019:3196 Oct 24, 2019
firefox · Ubuntu 18.04.6 LTS (bionic) 70.0+build2-0ubuntu0.18.04.1 firefox 70.0+build2-0ubuntu0.18.04.1 Jul 9, 2020
firefox · Ubuntu 20.04 LTS (focal) 70.0+build2-0ubuntu1 firefox 70.0+build2-0ubuntu1 Jul 9, 2020
firefox · ol 8 0:68.2.0-2.0.1.el8_0 ELSA-2019-3196 Oct 24, 2019
firefox-geckodriver · Ubuntu 18.04.6 LTS (bionic) 70.0+build2-0ubuntu0.18.04.1 firefox-geckodriver 70.0+build2-0ubuntu0.18.04.1 Jul 9, 2020
firefox-geckodriver · Ubuntu 20.04 LTS (focal) 70.0+build2-0ubuntu1 firefox-geckodriver 70.0+build2-0ubuntu1 Jul 9, 2020
firefox-mozsymbols · Ubuntu 18.04.6 LTS (bionic) 70.0+build2-0ubuntu0.18.04.1 firefox-mozsymbols 70.0+build2-0ubuntu0.18.04.1 Jul 9, 2020
firefox-mozsymbols · Ubuntu 20.04 LTS (focal) 70.0+build2-0ubuntu1 firefox-mozsymbols 70.0+build2-0ubuntu1 Jul 9, 2020
thunderbird · RHEL 8 0:68.2.0-1.el8_0 RHSA-2019:3237 Oct 29, 2019
thunderbird · Ubuntu 18.04.6 LTS (bionic) 1:68.2.1+build1-0ubuntu0.18.04.1 thunderbird 1:68.2.1+build1-0ubuntu0.18.04.1 Oct 22, 2019
thunderbird · ol 8 0:68.2.0-1.0.1.el8_0 ELSA-2019-3237 Oct 30, 2019
thunderbird-gnome-support · Ubuntu 18.04.6 LTS (bionic) 1:68.2.1+build1-0ubuntu0.18.04.1 thunderbird-gnome-support 1:68.2.1+build1-0ubuntu0.18.04.1 Oct 22, 2019
thunderbird-mozsymbols · Ubuntu 18.04.6 LTS (bionic) 1:68.2.1+build1-0ubuntu0.18.04.1 thunderbird-mozsymbols 1:68.2.1+build1-0ubuntu0.18.04.1 Oct 22, 2019
xul-ext-calendar-timezones · Ubuntu 18.04.6 LTS (bionic) 1:68.2.1+build1-0ubuntu0.18.04.1 xul-ext-calendar-timezones 1:68.2.1+build1-0ubuntu0.18.04.1 Oct 22, 2019
xul-ext-gdata-provider · Ubuntu 18.04.6 LTS (bionic) 1:68.2.1+build1-0ubuntu0.18.04.1 xul-ext-gdata-provider 1:68.2.1+build1-0ubuntu0.18.04.1 Oct 22, 2019
xul-ext-lightning · Ubuntu 18.04.6 LTS (bionic) 1:68.2.1+build1-0ubuntu0.18.04.1 xul-ext-lightning 1:68.2.1+build1-0ubuntu0.18.04.1 Oct 22, 2019

Patch Radar data is free to use with attribution. Terms and how to credit it.

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.