CVE-2020-25723

Se encontró un problema de aserción alcanzable en el código de emulación USB EHCI de QEMU. Podría ocurrir mientras se procesan las peticiones USB debido a una falta de manejo del fallo del mapa de memoria DMA. Un usuario privilegiado malicioso dentro del invitado puede abusar de este fallo para enviar peticiones USB falsas y bloquear el proceso QEMU en el host, resultando en una denegación de servicio

A reachable assertion vulnerability was found in the USB EHCI emulation code of QEMU. This issue occurs while processing USB requests due to missed handling of DMA memory map failure. This flaw allows a malicious privileged user within the guest to send bogus USB requests and crash the QEMU process on the host, resulting in a denial of service. The highest threat from this vulnerability is to system availability.

Alexander Bulekov discovered that QEMU incorrectly handled SDHCI device emulation. An attacker inside the guest 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. Sergej Schumilo, Cornelius Aschermann, and Simon Wrner discovered that QEMU incorrectly handled USB device emulation. An attacker inside the guest could use this issue to cause QEMU to crash, resulting in a denial of service. Various other issues were also addressed.