USN-4323-1: Firefox vulnerabilities

07 April 2020

Firefox could be made to crash or run programs as your login if it opened a malicious website.



  • firefox - Mozilla Open Source web browser


Multiple security issues were discovered in Firefox. If a user were
tricked in to opening a specially crafted website, an attacker could
potentially exploit these to cause a denial of service, obtain sensitive
information, or execute arbitrary code. (CVE-2020-6821, CVE-2020-6822,
CVE-2020-6824, CVE-2020-6825, CVE-2020-6826)

It was discovered that extensions could obtain auth codes from OAuth login
flows in some circumstances. If a user were tricked in to installing a
specially crafted extension, an attacker could potentially exploit this to
obtain access to the user's account. (CVE-2020-6823)

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 19.10
Ubuntu 18.04
Ubuntu 16.04

After a standard system update you need to restart Firefox to make
all the necessary changes.

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