A flaw was found in grub2, prior to version 2.06. An attacker may use the GRUB 2 flaw to hijack and tamper the GRUB verification process. This flaw also allows the bypass of Secure Boot protections. In order to load an untrusted or modified kernel, an attacker would first need to establish access to the system such as gaining physical access, obtain the ability to alter a pxe-boot network, or have remote access to a networked system with root access. With this access, an attacker could then craft a string to cause a buffer overflow by injecting a malicious payload that leads to arbitrary code execution within GRUB. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
Se encontró un fallo en grub2, versiones anteriores a 2.06. Un atacante puede usar el fallo de GRUB 2 para secuestrar y manipular el proceso de verificación de GRUB. Este fallo también permite omitir las protecciones de Secure Boot. A fin de cargar un kernel no confiable o modificado, un atacante primero necesitaría establecer acceso al sistema, tal y como conseguir acceso físico, obtener la capacidad de alterar una red pxe-boot o tener acceso remoto a un sistema de red con acceso root. Con este acceso, un atacante podría diseñar una cadena para causar un desbordamiento del búfer al inyectar una carga útil maliciosa que conlleve a una ejecución de código arbitraria dentro de GRUB. La mayor amenaza de esta vulnerabilidad es la confidencialidad e integridad de los datos, así como la disponibilidad del sistema
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
| Attack Vector | LOCAL |
|---|---|
| Attack Complexity | LOW |
| Privileges Required | HIGH |
| User Interaction | NONE |
| Scope | CHANGED |
| Confidentiality Impact | HIGH |
| Integrity Impact | HIGH |
| Availability Impact | HIGH |
AV:L/AC:L/Au:N/C:P/I:P/A:P
| Access Vector | LOCAL |
|---|---|
| Access Complexity | LOW |
| Authentication | NONE |
| Confidentiality Impact | PARTIAL |
| Integrity Impact | PARTIAL |
| Availability Impact | PARTIAL |
| Source | Type | Description |
|---|---|---|
| [email protected] | Primary |
en
CWE-120
|
| Vendor | Product | Version | Update | Type |
|---|---|---|---|---|
| gnu | grub2 | * | <built-in method update of dict object at 0x72a9cc7ef580> | Application |
| debian | debian_linux | 10.0 | <built-in method update of dict object at 0x72a9cd0c3cc0> | Operating System |
| opensuse | leap | 15.1 | <built-in method update of dict object at 0x72a9b0db5140> | Operating System |
| opensuse | leap | 15.2 | <built-in method update of dict object at 0x72a9cc60e000> | Operating System |
| vmware | photon_os | * | <built-in method update of dict object at 0x72a9cc7ed800> | Operating System |
| Vulnerable | CPE |
|---|---|
| Yes | cpe:2.3:a:gnu:grub2:*:*:*:*:*:*:*:* |
| Vulnerable | CPE |
|---|---|
| Yes | cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* |
| Vulnerable | CPE |
|---|---|
| Yes | cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:opensuse:leap:15.2:*:*:*:*:*:*:* |
| Vulnerable | CPE |
|---|---|
| Yes | cpe:2.3:o:vmware:photon_os:*:*:*:*:*:*:*:* |