PwnKit Local Privilege Escalation Vulnerability polkit’s pkexec (CVE-2021-4034)
A memory corruption vulnerability (CVE-2021-4034) in PolKit, a component used in major Linux distributions and some Unix-like operating systems, can be easily exploited by local unprivileged users to gain full root privileges.
Patch for Ubuntu is Available
If you don’t have any patch please remove suid bit from pxexec tool with this command
chmod 0755 /usr/bin/pkexec