Security updates for Wednesday

Security updates have been issued by CentOS (screen), Debian (clamav, courier-authlib, and tomcat9), Red Hat (thunderbird), SUSE (clamav, glibc, kernel, open-iscsi, opensc, spamassassin, thunderbird, wpa_supplicant, and xorg-x11-server), and Ubuntu (linux, linux-aws, linux-aws-5.4, linux-azure, linux-azure-5.4, linux-gcp, linux-gcp-5.4, linux-gke-5.4, linux-gkeop, linux-gkeop-5.4, linux-hwe-5.4, linux-kvm, linux-oracle, linux-oracle-5.4, linux-raspi, linux-raspi-5.4, linux, linux-aws, linux-aws-hwe, linux-azure, linux-azure-4.15, linux-dell300x, linux-gcp, linux-gcp-4.15, linux-kvm, linux-oracle, linux-raspi2, linux-snapdragon, linux, linux-aws, linux-azure, linux-gcp, linux-hwe-5.8, linux-kvm, linux-oracle, linux-raspi, linux, linux-aws, linux-kvm, linux-lts-xenial, linux-raspi2, linux-snapdragon, linux-oem-5.10, linux-oem-5.6, nettle, and xorg-server, xorg-server-hwe-16.04, xorg-server-hwe-18.04).