CVE-2020-6819: Mozilla Firefox And Thunderbird Use-After-Free Vulnerability
CVE-2020-6819 · Severity: critical · CVSS 8.1 · Exploited in the wild · Published 2021-11-03
A race condition in the nsDocShell destructor in Mozilla Firefox and Thunderbird can lead to a use-after-free vulnerability. This flaw allows for potential remote code execution or unspecified impacts under certain conditions. Mozilla has acknowledged targeted attacks in the wild exploiting this vulnerability.
Yes. CVE-2020-6819 is known to be exploited in the wild, first recorded on 3 November 2021. Treat it as urgent.
How severe is CVE-2020-6819?
Critical severity, with a CVSS score of 8.1, published 3 November 2021.
Which products and versions are affected?
Mozilla Firefox < 74.0.1; Mozilla Firefox ESR < 68.6.1; Mozilla Thunderbird < 68.7.0.
Is there a fix for CVE-2020-6819?
A patch was published on 2020-04-24: Fixed in Firefox 74.0.1, Firefox ESR 68.6.1, and Thunderbird 68.7.0 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2020-6819 attacked?
It is attacked over the network, in a network appliance.
Am I affected by CVE-2020-6819?
Check whether you run Mozilla Firefox or Mozilla Thunderbird. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Affected products
Mozilla Firefox < 74.0.1
Mozilla Firefox ESR < 68.6.1
Mozilla Thunderbird < 68.7.0
Timeline
2020-04-24: disclosed: NVD Published Date
2021-11-03: kev added: Added to CISA Known Exploited Vulnerabilities Catalog
2020-04-24: patched: Fixed in Firefox 74.0.1, Firefox ESR 68.6.1, and Thunderbird 68.7.0
exploited: Mozilla reported awareness of targeted attacks in the wild.