Moderate: systemd security update (Amazon Linux 2)

Package updates are available for Amazon Linux 2 that fix the following vulnerabilities: CVE-2019-3815: A memory leak was discovered in the backport of fixes for CVE-2018-16864 in Red Hat Enterprise Linux. Function dispatch_message_real() in journald-server.c does not free the memory allocated by set_iovec_field_free() to store the `_CMDLINE=` entry. A local attacker may use this flaw to make systemd-journald crash. 1666690: CVE-2019-3815 systemd: memory leak in journald-server.c introduced by fix for CVE-2018-16864 CVE-2019-20386: A memory leak was discovered in the systemd-login when a power-switch event is received. A physical attacker may trigger one of these events and leak bytes due to a missing free. 1793979: CVE-2019-20386 systemd: memory leak in button_open() in login/logind-button.c when udev events are received CVE-2018-15686: It was discovered that systemd is vulnerable to a state injection attack when deserializing the state of a service. Properties longer than LINE_MAX are not correctly parsed and an attacker may abuse this flaw in particularly configured services to inject, change, or corrupt the service state. 1639071: CVE-2018-15686 systemd: line splitting via fgets() allows for state injection during daemon-reexec