Use After Free in Mozilla Firefox

CVE-2020-15683

Mozilla developers and community members reported memory safety bugs present in Firefox 81 and Firefox ESR 78.3. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox ESR < 78.4, Firefox < 82, and Thunderbird < 78.4.

Vulnerability class: Use-After-Free

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.027 (85.2th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 85th percentile — 85.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2020-15683: held from 0.027 to 0.027.

EPSS over last 30 days · oldest: 0.027 · newest: 0.027 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2020-15683?
CVE-2020-15683 is a critical-severity vulnerability in Mozilla Firefox, classified under Use After Free. CVSS score: 9.8/10. Published 2020-10-22.
How severe is CVE-2020-15683?
Critical severity. CVSS v3 base score is 9.8 out of 10.