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Known exploited vulnerability

CVE-2020-6819

highCVSS 3.1 8.1In CISA KEVEPSS 3.0%Published · Mozilla

The short answer

CVE-2020-6819 affects Mozilla Thunderbird and is rated high (CVSS 8.1). CISA added it to the Known Exploited Vulnerabilities catalog on 2021-11-03: attackers are using it, so patch it first.

What it is

Under certain conditions, when running the nsDocShell destructor, 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.

Weakness: CWE-362, CWE-416.

Severity

8.1 high

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploited (CISA KEV)

Yes, since Nov 3, 2021

Federal due date May 3, 2022

EPSS, next 30 days

3.0%

Higher than 88% of scored CVEs

How it can be exploited

Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

What CISA says to do

Apply updates per vendor instructions.

Affected products

Thunderbird, Firefox, Firefox ESR. NVD's record lists the exact affected versions.

References

Questions

Is CVE-2020-6819 being exploited?

Yes. CISA added CVE-2020-6819 to its Known Exploited Vulnerabilities catalog on 2021-11-03, with a federal remediation due date of 2022-05-03.

How do I fix CVE-2020-6819?

CISA's required action: Apply updates per vendor instructions.

From NVD, CISA KEV, FIRST EPSS and OSV.dev, checked . Status on NVD: Analyzed. The description is NVD's text, quoted as published.

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