A flaw was found in the 9p passthrough filesystem (9pfs) implementation in QEMU. The 9pfs server did not prohibit opening special files on the host side, potentially allowing a malicious client to escape from the exported 9p tree by creating and opening a device file in the shared folder.
Se encontró una falla en la implementación del sistema de archivos de paso 9p (9pfs) en QEMU. El servidor 9pfs no prohibía la apertura de archivos especiales en el lado del host, lo que potencialmente permitía que un cliente malicioso escapara del árbol 9p exportado creando y abriendo un archivo de dispositivo en la carpeta compartida.
Gaoning Pan and Xingwei Li discovered that QEMU incorrectly handled the USB xHCI controller device. A privileged guest attacker could possibly use this issue to cause QEMU to crash, leading to a denial of service. This issue only affected Ubuntu 20.04 LTS and Ubuntu 22.04 LTS. It was discovered that QEMU incorrectly handled the TCG Accelerator. A local attacker could use this issue to cause QEMU to crash, leading to a denial of service, or possibly execute arbitrary code and escalate privileges. This issue only affected Ubuntu 20.04 LTS.