CVE-2021-4140
thunderbird - security update
10.0
CRITICAL
CVSS 3.1
EPSS 0.07%
Description
It was possible to construct specific XSLT markup that would be able to bypass an iframe sandbox. This vulnerability affects Firefox ESR < 91.5, Firefox < 96, and Thunderbird < 91.5.
How to fix CVE-2021-4140
To remediate CVE-2021-4140, upgrade the affected package to a fixed version below.
- Debian/firefox-esr—upgrade to 91.5.0esr-1~deb11u1 or later
- —upgrade to 91.5.0esr-1~deb9u1 or later
- —upgrade to 91.5.0esr-1~deb10u1 or later
- —upgrade to 1:91.5.0-2~deb11u1 or later
- —upgrade to 1:91.5.0-1~deb9u1 or later
- —upgrade to 1:91.5.0-2~deb10u1 or later
Is CVE-2021-4140 being exploited?
Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.
Affected packages (6)
- from 0, < 91.5.0esr-1~deb11u1
- from 0, < 91.5.0esr-1~deb9u1
- from 0, < 91.5.0esr-1~deb10u1
- from 0, < 1:91.5.0-2~deb11u1
- from 0, < 1:91.5.0-1~deb9u1
- from 0, < 1:91.5.0-2~deb10u1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | CRITICAL10.0 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |