Use After Free in Mozilla Firefox

CVE-2017-5402

A use-after-free can occur when events are fired for a "FontFace" object after the object has been already been destroyed while working with fonts. This results in a potentially exploitable crash. This vulnerability affects Firefox < 52, Firefox ESR < 45.8, Thunderbird < 52, and Thunderbird < 45.8.

Vulnerability class: Use-After-Free

EPSS: 0.029 (85.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2017-5402?
CVE-2017-5402 is a critical-severity vulnerability in Mozilla Firefox, classified under Use After Free. CVSS score: 9.8/10. Published 2018-06-11.
How severe is CVE-2017-5402?
Critical severity. CVSS v3 base score is 9.8 out of 10.