Canonical has released updates for the 5.4 kernel used in the two latest LTS releases of Ubuntu (18.04 and 20.04) on all supported architectures and platforms. 

There are 12 vulnerabilities patched, which include a fix for CVE-2021-33624 (marked Medium), an issue that could allow an attacker to expose sensitive information. Another issue fixed was CVE-2021-3679 (marked Low), which could lead to a Denial of Service attack. Another Denial of Service attack vulnerability patch is CVE-2021-38199 (marked Medium).

Other patched CVE's include CVE-2021-38204 (Low), CVE-2021-38160 (Medium), CVE-2021-37576 (Medium), CVE-2021-38201 (Medium), CVE-2021-34556 (Medium), CVE-2021-35477 (Medium), CVE-2021-41073 (High), CVE-2021-38205 (Low), and CVE-2021-37159 (Low).

Canonical is urging all users of Ubuntu 21.04 (linux-image-generic 5.11.0.37.39), 20.04 (linux-image-generic 5.4.0.88.92), and 18.04 (linux-image-generic 5.4.0-87.98~18.04.1) to update their kernel versions immediately. Make sure to log into your servers and/or desktops and issue the commands sudo apt-get update and sudo apt-get full-upgrade . Once the upgrade completes, make sure to reboot any affected machines so the changes will take effect.