CVE-2018-16888

Se ha descubierto que systemd no comprueba correctamente el contenido de archivos PIDFile antes de emplearlo para terminar procesos. Cuando un servicio se ejecuta desde un usuario sin privilegios (p.ej. un campo de usuario establecido en el archivo de servicio) un atacante local capaz de escribir en el archivo PIDFile del servicio mencionado podría aprovechar este fallo para engañar a systemd para que termine otros servicios y/o procesos privilegiados. Las versiones anteriores a la v237 son vulnerables.

It was discovered systemd does not correctly check the content of PIDFile files before using it to kill processes. When a service is run from an unprivileged user (e.g. User field set in the service file), a local attacker who is able to write to the PIDFile of the mentioned service may use this flaw to trick systemd into killing other services and/or privileged processes.

It was discovered that systemd incorrectly handled certain PIDFile files. A local attacker could possibly use this issue to trick systemd into killing privileged processes. This issue only affected Ubuntu 16.04 LTS. It was discovered that systemd incorrectly handled certain udevadm trigger commands. A local attacker could possibly use this issue to cause systemd to consume resources, leading to a denial of service. Various other issues were also addressed.