CVE-2020-25647

Se encontró un fallo en grub2 en versiones anteriores a 2.06. Durante la inicialización del dispositivo USB, los descriptores se leen con muy poca comprobación de límites y se supone que el dispositivo USB proporciona valores saneados. Si es explotada apropiadamente, un atacante podría desencadenar una corrupción en memoria que conlleva a una ejecución de código arbitraria, permitiendo omitir el mecanismo de Secure Boot. La mayor amenaza de esta vulnerabilidad es la confidencialidad e integridad de los datos, así como la disponibilidad del sistema

A flaw was found in grub2. During USB device initialization, descriptors are read with very little bounds checking and assumes the USB device is providing sane values. If properly exploited, an attacker could trigger memory corruption leading to arbitrary code execution allowing a bypass of the Secure Boot mechanism. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

The grub2 packages provide version 2 of the Grand Unified Boot Loader, a highly configurable and customizable boot loader with modular architecture. The packages support a variety of kernel formats, file systems, computer architectures, and hardware devices. Issues addressed include buffer overflow, out of bounds write, and use-after-free vulnerabilities.