CVE-2020-6820

Known Exploited

Description

Under certain conditions, when handling a ReadableStream, a race condition can cause a use-after-free. We are aware of targeted attacks in the wild abusing this flaw. This vulnerability affects Thunderbird < 68.7.0, Firefox < 74.0.1, and Firefox ESR < 68.6.1.

Category

8.1
CVSS
Severity: High
CVSS 3.1 •
CVSS 2.0 •
EPSS 4.41% Top 15%
KEV Since 
Vendor Advisory ubuntu.com Vendor Advisory mozilla.org Vendor Advisory mozilla.org
Affected: Mozilla Thunderbird
Affected: Mozilla Firefox
Affected: Mozilla Firefox ESR
Published at:
Updated at:

References

Link Tags
https://www.mozilla.org/security/advisories/mfsa2020-14/ vendor advisory
https://www.mozilla.org/security/advisories/mfsa2020-11/ vendor advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1626728 issue tracking permissions required
https://usn.ubuntu.com/4335-1/ third party advisory vendor advisory

Frequently Asked Questions

What is the severity of CVE-2020-6820?
CVE-2020-6820 has been scored as a high severity vulnerability.
How to fix CVE-2020-6820?
To fix CVE-2020-6820, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2020-6820 being actively exploited in the wild?
It is confirmed that CVE-2020-6820 is actively exploited. Be extra cautious if you are using vulnerable components. According to its EPSS score, there is a ~4% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2020-6820?
CVE-2020-6820 affects Mozilla Thunderbird, Mozilla Firefox, Mozilla Firefox ESR.
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