CVE-2020-15705 GRUB2: avoid loading unsigned kernels when GRUB is booted directly under secureboot without shim

2020-07-2900:00:00

CWE-347

canonical

www.cve.org

CVSS3

6.4

Attack Vector

LOCAL

Attack Complexity

HIGH

Privileges Required

HIGH

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H

AI Score

Confidence

High

EPSS

0.001

Percentile

33.3%

JSON

GRUB2 fails to validate kernel signature when booted directly without shim, allowing secure boot to be bypassed. This only affects systems where the kernel signing certificate has been imported directly into the secure boot database and the GRUB image is booted directly without the use of shim. This issue affects GRUB2 version 2.04 and prior versions.

CNA Affected

[
  {
    "product": "grub2 in Ubuntu",
    "vendor": "Ubuntu",
    "versions": [
      {
        "lessThan": "2.04-1ubuntu26.1",
        "status": "affected",
        "version": "20.04 LTS",
        "versionType": "custom"
      },
      {
        "lessThan": "2.02-2ubuntu8.16",
        "status": "affected",
        "version": "18.04 LTS",
        "versionType": "custom"
      },
      {
        "lessThan": "2.02~beta2-36ubuntu3.26",
        "status": "affected",
        "version": "16.04 LTS",
        "versionType": "custom"
      },
      {
        "lessThan": "2.02~beta2-9ubuntu1.20",
        "status": "affected",
        "version": "14.04 ESM",
        "versionType": "custom"
      }
    ]
  }
]