CVE-2018-7550

La función load_multiboot en hw/i386/multiboot.c en Quick Emulator (también conocido como QEMU) permite que usuarios locales invitados del sistema operativo ejecuten código arbitrario en el host QEMU mediante un valor mh_load_end_addr mayor que mh_bss_end_addr. Esto desencadena un acceso de lectura o escritura a la memoria fuera de límites.

Quick Emulator (QEMU), compiled with the PC System Emulator with multiboot feature support, is vulnerable to an OOB r/w memory access issue. The issue could occur while loading a kernel image during the guest boot, if mh_load_end_addr address is greater than the mh_bss_end_addr address. A user or process could use this flaw to potentially achieve arbitrary code execution on a host.

Cyrille Chatras discovered that QEMU incorrectly handled certain PS2 values during migration. An attacker could possibly use this issue to cause QEMU to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 18.04 LTS. Cyrille Chatras discovered that QEMU incorrectly handled multiboot. An attacker could use this issue to cause QEMU to crash, resulting in a denial of service, or possibly execute arbitrary code on the host. In the default installation, when QEMU is used with libvirt, attackers would be isolated by the libvirt AppArmor profile. Various other issues were also addressed.