A new release of the Ubuntu Cloud Images for stable Ubuntu release 18.04 LTS (Bionic Beaver) is available at [1]. These new images superseded the existing images [2]. Images are available for download or immediate use on EC2 via publish AMI ids. Users who wish to update their existing installations can do so with:
   'sudo apt-get update && sudo apt-get dist-upgrade && sudo reboot'.

The following packages have been updated. Please see the full changelogs
for a complete listing of changes:
 * grub2: 2.02-2ubuntu8.19 => 2.02-2ubuntu8.20 
 * grub2-signed: 1.93.21+2.02-2ubuntu8.19 => 1.93.22+2.02-2ubuntu8.20 
 * krb5: 1.16-2ubuntu0.1 => 1.16-2ubuntu0.2 
 * systemd: 237-3ubuntu10.42 => 237-3ubuntu10.43 


The following is a complete changelog for this image.
new: {}
removed: {}
changed: ['grub-common', 'grub-efi-amd64', 'grub-efi-amd64-bin', 'grub-efi-amd64-signed', 'grub-pc', 'grub-pc-bin', 'grub2-common', 'krb5-locales', 'libgssapi-krb5-2:amd64', 'libk5crypto3:amd64', 'libkrb5-3:amd64', 'libkrb5support0:amd64', 'libnss-systemd:amd64', 'libpam-systemd:amd64', 'libsystemd0:amd64', 'libudev1:amd64', 'systemd', 'systemd-sysv', 'udev']
new snaps: {}
removed snaps: {}
changed snaps: []
==== grub2: 2.02-2ubuntu8.19 => 2.02-2ubuntu8.20 ====
====     grub-common grub-efi-amd64 grub-efi-amd64-bin grub-pc grub-pc-bin grub2-common
  * Avoid "EFI stub: FIRMWARE BUG" message when booting >= 5.7 kernels
    on arm64 by setting the image base address before jumping to the
    PE/COFF entry point LP: #1900774
  * Fix tftp timeouts when fetching large files. LP: #1900773
==== grub2-signed: 1.93.21+2.02-2ubuntu8.19 => 1.93.22+2.02-2ubuntu8.20 ====
====     grub-efi-amd64-signed
==== krb5: 1.16-2ubuntu0.1 => 1.16-2ubuntu0.2 ====
====     krb5-locales libgssapi-krb5-2:amd64 libk5crypto3:amd64 libkrb5-3:amd64 libkrb5support0:amd64
  * SECURITY UPDATE: Unbounded recursion
    - debian/patches/CVE-2020-28196.patch: adds recursion limit for ASN.1
      indefinite lenghts in src/lib/krb5/asn.1/asn1_encode.c.
    - CVE-2020-28196
==== systemd: 237-3ubuntu10.42 => 237-3ubuntu10.43 ====
====     libnss-systemd:amd64 libpam-systemd:amd64 libsystemd0:amd64 libudev1:amd64 systemd systemd-sysv udev
  [ Guilherme G. Piccoli ]
  * d/p/lp1830746-bump-mlock-ulimit-to-64Mb.patch:
    - Bump the memlock limit to match Focal and newer releases (LP: #1830746)
      https://git.launchpad.net/~ubuntu-core-dev/ubuntu/+source/systemd/commit/?id=61adb797642f3dd2e5c14f7914c2949c665cefe8
  [ Victor Manuel Tapia King ]
  * d/p/lp1896614-core-Avoid-race-when-starting-dbus-services.patch:
    - Fix race when starting dbus services (LP: #1896614)
      https://git.launchpad.net/~ubuntu-core-dev/ubuntu/+source/systemd/commit/?id=373cb6ccd6978a7112bbfd7e5cf4f703a9f8448e
  [ Dan Streetman ]
  * d/t/*,
    d/p/lp1892358/0001-test-increase-qemu-timeout-for-TEST-08-and-TEST-09.patch,
    d/p/lp1892358/0002-test-increase-timeout-for-TEST-17-UDEV-WANTS.patch,
    d/p/lp1892358/0003-test-increase-qemu-timeout-for-TEST-18-and-TEST-19.patch:
    - Increase QEMU_TIMEOUT on 'upstream' autopkgtest tests
    - Pull latest tests from newer releases to fix false negatives
    - Blacklist flaky 'upstream' TEST-03
      (LP: #1892358)
      https://git.launchpad.net/~ubuntu-core-dev/ubuntu/+source/systemd/commit/?id=9fd8391c2499e163515b629a8ca5790898fc599d
      https://git.launchpad.net/~ubuntu-core-dev/ubuntu/+source/systemd/commit/?id=d1756b3e1c3e625ed7162cff4909e7a29c315051
      https://git.launchpad.net/~ubuntu-core-dev/ubuntu/+source/systemd/commit/?id=37f8d73516a84e85e4057d6a92204b4a174af718
      https://git.launchpad.net/~ubuntu-core-dev/ubuntu/+source/systemd/commit/?id=229ed2076eb773efc548035262b8b8009bf89207
      https://git.launchpad.net/~ubuntu-core-dev/ubuntu/+source/systemd/commit/?id=f2d7b1f952667316cc07a4b3c5010e66ace07a90
      https://git.launchpad.net/~ubuntu-core-dev/ubuntu/+source/systemd/commit/?id=659befe61bbfeb7afc9efa24458c9745412d7c6d

--
[1] http://cloud-images.ubuntu.com/releases/bionic/release-20201123/
[2] http://cloud-images.ubuntu.com/releases/bionic/release-20201117/