Oracle Linux: CVE-2019-6454: ELSA-2019-0990: systemd security and bug fix update (MODERATE) (Multiple Advisories)

Description

An issue was discovered in sd-bus in systemd 239. bus_process_object() in libsystemd/sd-bus/bus-objects.c allocates a variable-length stack buffer for temporarily storing the object path of incoming D-Bus messages. An unprivileged local user can exploit this by sending a specially crafted message to PID1, causing the stack pointer to jump over the stack guard pages into an unmapped memory region and trigger a denial of service (systemd PID1 crash and kernel panic). It was discovered that systemd allocates a buffer large enough to store the path field of a dbus message without performing enough checks. A local attacker may trigger this flaw by sending a dbus message to systemd with a large path making systemd crash or possibly elevating his privileges.