Provide references for CVE-2021-3939.
Where can I find more information about CVE-2021-3939?
References are available at: https://ubuntu.com/security/notices/USN-5149-1, https://bugs.launchpad.net/ubuntu/+source/accountsservice/+bug/1950149, http://packetstormsecurity.com/files/172848/Ubuntu-accountsservice-Double-Free-Memory-Corruption.html.