CVE-2021-43542
6.5
MEDIUM
CVSS 3.1
EPSS 0.73%
Description
Using XMLHttpRequest, an attacker could have identified installed applications by probing error messages for loading external protocols. This vulnerability affects Thunderbird < 91.4.0, Firefox ESR < 91.4.0, and Firefox < 95.
How to fix CVE-2021-43542
To remediate CVE-2021-43542, upgrade the affected package to a fixed version below.
- Debian/firefox-esr—upgrade to 91.4.1esr-1~deb11u1 or later
- —upgrade to 1:91.4.1-1~deb11u1 or later
Is CVE-2021-43542 being exploited?
Low — EPSS is 0.7%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- from 0, < 91.4.1esr-1~deb11u1
- from 0, < 1:91.4.1-1~deb11u1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N |