Provide references for CVE-2021-3899.
Where can I find more information about CVE-2021-3899?
References are available at: https://bugs.launchpad.net/ubuntu/+source/apport/+bug/1948376, https://ubuntu.com/security/notices/USN-5427-1, https://www.cve.org/CVERecord?id=CVE-2021-3899.