Use After Free in Mozilla Firefox

CVE-2020-12405

When browsing a malicious page, a race condition in our SharedWorkerService could occur and lead to a potentially exploitable crash. This vulnerability affects Thunderbird < 68.9.0, Firefox < 77, and Firefox ESR < 68.9.

Vulnerability class: Race Condition

EPSS: 0.014 (68.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2020-12405?
CVE-2020-12405 is a medium-severity vulnerability in Mozilla Firefox, classified under Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). CVSS score: 5.3/10. Published 2020-07-09.
How severe is CVE-2020-12405?
Medium severity. CVSS v3 base score is 5.3 out of 10.