What is CVE-2021-4128?

CVE-2021-4128 is a medium-severity vulnerability in Apple macOS, classified under Use After Free. CVSS score: 6.5/10. Published 2022-12-22.

How severe is CVE-2021-4128?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Use After Free in Apple macOS

CVE-2021-4128

When transitioning in and out of fullscreen mode, a graphics object was not correctly protected; resulting in memory corruption and a potentially exploitable crash.<br>*This bug only affects Firefox on MacOS. Other operating systems are unaffected.*. This vulnerability affects Firefox < 95.

Vulnerability class: Use-After-Free

EPSS: 0.005 (42.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

Affected products

Apple Macos
Mozilla Firefox — versions unspecified

Weakness classification (CWE)

CWE-416 — Use After Free

References

security@mozilla.org (Vendor Advisory)
security@mozilla.org (Exploit, Patch, Issue Tracking, Vendor Advisory)

Frequently asked questions

What is CVE-2021-4128?: CVE-2021-4128 is a medium-severity vulnerability in Apple macOS, classified under Use After Free. CVSS score: 6.5/10. Published 2022-12-22.
How severe is CVE-2021-4128?: Medium severity. CVSS v3 base score is 6.5 out of 10.