CVE-2021-20196

Se encontró un fallo de desreferencia de puntero NULL en el emulador floppy disk de QEMU. Este problema ocurre mientras se procesan comandos de ioport de lectura y escritura si la unidad de disquete seleccionada no es inicializada con un dispositivo de bloque. Este fallo permite a un usuario invitado privilegiado bloquear el proceso QEMU en el host, resultando en una denegación de servicio. La mayor amenaza de esta vulnerabilidad es la disponibilidad del sistema

Gaoning Pan discovered that QEMU incorrectly handled the floppy disk emulator. An attacker inside the guest could use this issue to cause QEMU to crash, resulting in a denial of service. Gaoning Pan discovered that the QEMU vmxnet3 NIC emulator incorrectly handled certain values. An attacker inside the guest could use this issue to cause QEMU to crash, resulting in a denial of service. It was discovered that the QEMU vhost-user GPU device contained several security issues. An attacker inside the guest could use these issues to cause QEMU to crash, resulting in a denial of service, leak sensitive information, or possibly execute arbitrary code. This issue only affected Ubuntu 21.10.