CVE-2021-23999
8.8
HIGH
CVSS 3.1
EPSS 0.24%
Description
If a Blob URL was loaded through some unusual user interaction, it could have been loaded by the System Principal and granted additional privileges that should not be granted to web content. This vulnerability affects Firefox ESR < 78.10, Thunderbird < 78.10, and Firefox < 88.
How to fix CVE-2021-23999
To remediate CVE-2021-23999, upgrade the affected package to a fixed version below.
- Debian/firefox-esr—upgrade to 78.10.0esr-1 or later
- —upgrade to 1:78.10.0-1 or later
Is CVE-2021-23999 being exploited?
Low — EPSS is 0.2%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- from 0, < 78.10.0esr-1
- from 0, < 1:78.10.0-1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH8.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |