ubuntu-cve-2020-27779
Vulnerability from osv_ubuntu
Published
2021-03-02 18:00
Modified
2025-09-08 16:46
Summary
Details

A flaw was found in grub2 in versions prior to 2.06. The cutmem command does not honor secure boot locking allowing an privileged attacker to remove address ranges from memory creating an opportunity to circumvent SecureBoot protections after proper triage about grub's memory layout. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

Severity
7.5 (High)
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H
7.5 (High)
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H
N/A (UNKNOWN)
medium
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "grub-efi-amd64-signed",
            "binary_version": "1.34.24+2.02~beta2-9ubuntu1.21"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:14.04:LTS",
        "name": "grub2-signed",
        "purl": "pkg:deb/ubuntu/grub2-signed@1.34.24?arch=source\u0026distro=esm-infra-legacy/trusty"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.22",
        "1.23",
        "1.24",
        "1.25",
        "1.26",
        "1.27",
        "1.30",
        "1.31",
        "1.32",
        "1.33",
        "1.34",
        "1.34.1",
        "1.34.2",
        "1.34.3",
        "1.34.4",
        "1.34.5",
        "1.34.6",
        "1.34.7",
        "1.34.8",
        "1.34.9",
        "1.34.13",
        "1.34.14",
        "1.34.16",
        "1.34.17",
        "1.34.18",
        "1.34.20",
        "1.34.22",
        "1.34.24"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "grub-efi-amd64-signed",
            "binary_version": "1.167~18.04.5+2.04-1ubuntu44.1.2"
          },
          {
            "binary_name": "grub-efi-arm64-signed",
            "binary_version": "1.167~18.04.5+2.04-1ubuntu44.1.2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:18.04:LTS",
        "name": "grub2-signed",
        "purl": "pkg:deb/ubuntu/grub2-signed@1.167~18.04.5?arch=source\u0026distro=bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.167~18.04.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.85",
        "1.86",
        "1.87",
        "1.89",
        "1.91",
        "1.92",
        "1.93",
        "1.93.1",
        "1.93.2",
        "1.93.3",
        "1.93.4",
        "1.93.5",
        "1.93.7",
        "1.93.8",
        "1.93.10",
        "1.93.11",
        "1.93.13",
        "1.93.14",
        "1.93.15",
        "1.93.16",
        "1.93.18",
        "1.93.19",
        "1.93.20",
        "1.93.21",
        "1.93.22",
        "1.93.24",
        "1.167~18.04.1",
        "1.167~18.04.3"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "grub-efi-amd64",
            "binary_version": "2.04-1ubuntu44.1.2"
          },
          {
            "binary_name": "grub-efi-amd64-bin",
            "binary_version": "2.04-1ubuntu44.1.2"
          },
          {
            "binary_name": "grub-efi-arm64",
            "binary_version": "2.04-1ubuntu44.1.2"
          },
          {
            "binary_name": "grub-efi-arm64-bin",
            "binary_version": "2.04-1ubuntu44.1.2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:18.04:LTS",
        "name": "grub2-unsigned",
        "purl": "pkg:deb/ubuntu/grub2-unsigned@2.04-1ubuntu44.1.2?arch=source\u0026distro=bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.04-1ubuntu44.1.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.04-1ubuntu44",
        "2.04-1ubuntu44.1"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "grub-efi-amd64-signed",
            "binary_version": "1.167.2+2.04-1ubuntu44.2"
          },
          {
            "binary_name": "grub-efi-arm64-signed",
            "binary_version": "1.167.2+2.04-1ubuntu44.2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "grub2-signed",
        "purl": "pkg:deb/ubuntu/grub2-signed@1.167.2?arch=source\u0026distro=focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.167.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.128",
        "1.129",
        "1.130",
        "1.131",
        "1.133",
        "1.134",
        "1.135",
        "1.136",
        "1.137",
        "1.138",
        "1.139",
        "1.140",
        "1.141",
        "1.142",
        "1.142.1",
        "1.142.3",
        "1.142.4",
        "1.142.5",
        "1.142.6",
        "1.142.8",
        "1.142.9",
        "1.142.10",
        "1.142.11",
        "1.167"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "grub-efi-amd64",
            "binary_version": "2.04-1ubuntu44.2"
          },
          {
            "binary_name": "grub-efi-amd64-bin",
            "binary_version": "2.04-1ubuntu44.2"
          },
          {
            "binary_name": "grub-efi-arm64",
            "binary_version": "2.04-1ubuntu44.2"
          },
          {
            "binary_name": "grub-efi-arm64-bin",
            "binary_version": "2.04-1ubuntu44.2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "grub2-unsigned",
        "purl": "pkg:deb/ubuntu/grub2-unsigned@2.04-1ubuntu44.2?arch=source\u0026distro=focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.04-1ubuntu44.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.04-1ubuntu44"
      ]
    }
  ],
  "aliases": [],
  "details": "A flaw was found in grub2 in versions prior to 2.06. The cutmem command does not honor secure boot locking allowing an privileged attacker to remove address ranges from memory creating an opportunity to circumvent SecureBoot protections after proper triage about grub\u0027s memory layout. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.",
  "id": "UBUNTU-CVE-2020-27779",
  "modified": "2025-09-08T16:46:27Z",
  "published": "2021-03-02T18:00:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2020-27779"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-4992-1"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2020-27779"
    }
  ],
  "related": [
    "USN-4992-1"
  ],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2020-27779"
  ]
}



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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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