CVE-2020-6820

Publication date 3 April 2020

Last updated 25 August 2025

Ubuntu priority

High

Why this priority?

Cvss 3 Severity Score

8.1 · High

Score breakdown

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.

Read the notes from the security team

Status

Package Ubuntu Release Status
thunderbird 20.04 LTS focal
Fixed 1:68.7.0+build1-0ubuntu1
19.10 eoan
Fixed 1:68.7.0+build1-0ubuntu0.19.10.1
18.04 LTS bionic
Fixed 1:68.7.0+build1-0ubuntu0.18.04.1
16.04 LTS xenial
Fixed 1:68.7.0+build1-0ubuntu0.16.04.2
14.04 LTS trusty Not in release
firefox 20.04 LTS focal
Fixed 75.0+build3-0ubuntu1
19.10 eoan
Fixed 74.0.1+build1-0ubuntu0.19.10.1
18.04 LTS bionic
Fixed 74.0.1+build1-0ubuntu0.18.04.1
16.04 LTS xenial
Fixed 74.0.1+build1-0ubuntu0.16.04.1
14.04 LTS trusty Not in release

Notes

tyhicks

mozjs contains a copy of the SpiderMonkey JavaScript engine

Severity score breakdown

Parameter Value
Base score 8.1 · High
Attack vector Network
Attack complexity High
Privileges required None
User interaction None
Scope Unchanged
Confidentiality High
Integrity impact High
Availability impact High
Vector CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

References

Related Ubuntu Security Notices (USN)

    • USN-4328-1
    • Thunderbird vulnerabilities
    • 13 April 2020
    • USN-4335-1
    • Thunderbird vulnerabilities
    • 21 April 2020

Other references