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TI-2020-16864 Aliases CVE-2020-27779GHSA-7p29-8vr2-rmvx

Improper authorization in grub2

Priority LOW 33CWE-285Published · Updated

Key facts

Attack vector
Local
Privileges required
High
User interaction
None
Attack complexity
High
Impact type
Security bypass
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 33 fixed, 1 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA, Red Hat and Microsoft. Impact type from CWE-285.

Summary

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.

Why it matters now

EPSS 0.0039 33rd percentileScored 2026-11-07
Fix Partial Red Hat: 13 advisoriesMicrosoft: 1 updateRed Hat: 33 fixed, 1 without a fix

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
—grub2grub 2.06—No fix listedCNA
  • grub2 Vendor— Affected grub 2.06 Fixed in — No fix listed CNA

CPE configurations NVD · 20

CPEVersionsRoleVendor
cpe:2.3:a:gnu:grub2:*:*:*:*:*:*:*:*before 2.06VulnerableGNU
cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*7.0VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*8.0VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_server_aus:7.2:*:*:*:*:*:*:*7.2VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_server_aus:7.3:*:*:*:*:*:*:*7.3VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_server_aus:7.4:*:*:*:*:*:*:*7.4VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_server_aus:7.6:*:*:*:*:*:*:*7.6VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_server_aus:7.7:*:*:*:*:*:*:*7.7VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_server_aus:8.2:*:*:*:*:*:*:*8.2VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_server_eus:7.6:*:*:*:*:*:*:*7.6VulnerableRed Hat
  • cpe:2.3:a:gnu:grub2:*:*:*:*:*:*:*:* Versions before 2.06 Vulnerable ·GNU
  • cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:* Versions 7.0 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* Versions 8.0 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_server_aus:7.2:*:*:*:*:*:*:* Versions 7.2 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_server_aus:7.3:*:*:*:*:*:*:* Versions 7.3 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_server_aus:7.4:*:*:*:*:*:*:* Versions 7.4 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_server_aus:7.6:*:*:*:*:*:*:* Versions 7.6 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_server_aus:7.7:*:*:*:*:*:*:* Versions 7.7 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_server_aus:8.2:*:*:*:*:*:*:* Versions 8.2 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_server_eus:7.6:*:*:*:*:*:*:* Versions 7.6 Vulnerable ·Red Hat
Show 10 more CPE
CPEVersionsRoleVendor
cpe:2.3:o:redhat:enterprise_linux_server_eus:7.7:*:*:*:*:*:*:*7.7VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_server_eus:8.1:*:*:*:*:*:*:*8.1VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_server_tus:7.4:*:*:*:*:*:*:*7.4VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_server_tus:7.6:*:*:*:*:*:*:*7.6VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_server_tus:7.7:*:*:*:*:*:*:*7.7VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_server_tus:8.2:*:*:*:*:*:*:*8.2VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:*7.0VulnerableRed Hat
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*33VulnerableFedoraproject
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*34VulnerableFedoraproject
cpe:2.3:a:netapp:ontap_select_deploy_administration_utility:-:*:*:*:*:*:*:*not specified by NVDVulnerableNetApp
  • cpe:2.3:o:redhat:enterprise_linux_server_eus:7.7:*:*:*:*:*:*:* Versions 7.7 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_server_eus:8.1:*:*:*:*:*:*:* Versions 8.1 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_server_tus:7.4:*:*:*:*:*:*:* Versions 7.4 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_server_tus:7.6:*:*:*:*:*:*:* Versions 7.6 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_server_tus:7.7:*:*:*:*:*:*:* Versions 7.7 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_server_tus:8.2:*:*:*:*:*:*:* Versions 8.2 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:* Versions 7.0 Vulnerable ·Red Hat
  • cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* Versions 33 Vulnerable ·Fedoraproject
  • cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* Versions 34 Vulnerable ·Fedoraproject
  • cpe:2.3:a:netapp:ontap_select_deploy_administration_utility:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp

Remediation

Red Hat 13 advisories

  • RHSA-2021:3675 Released 2021-09-28 · Red Hat rating Moderate
    shim and fwupd security update
    • Red Hat CodeReady Linux Builder EUS (v. 8.1) shim-unsigned-aarch64-15-7.el8_1, shim-unsigned-x64-15.4-4.el8_1
    • Red Hat Enterprise Linux BaseOS EUS (v. 8.1) fwupd-1.1.4-4.el8_1, shim-15.4-2.el8_1, shim-aa64-15.4-2.el8_1 +2
  • RHSA-2021:2790 Released 2021-07-20 · Red Hat rating Moderate
    shim and fwupd security update
    • Red Hat CodeReady Linux Builder EUS (v. 8.2) shim-unsigned-aarch64-15-7.el8_1, shim-unsigned-x64-15.4-4.el8_1
    • Red Hat Enterprise Linux BaseOS EUS (v. 8.2) fwupd-1.1.4-9.el8_2, shim-15.4-2.el8_1, shim-aa64-15.4-2.el8_1 +2
  • RHSA-2021:2566 Released 2021-06-29 · Red Hat rating Moderate
    fwupd security update
    • Red Hat Enterprise Linux BaseOS (v. 8) fwupd-1.5.9-1.el8_4
Show 10 more Red Hat advisories
  • RHSA-2021:1734 Released 2021-05-18 · Red Hat rating Moderate
    shim security update
    • Red Hat CodeReady Linux Builder (v. 8) shim-unsigned-aarch64-15-7.el8_1, shim-unsigned-x64-15.4-4.el8_1
    • Red Hat Enterprise Linux BaseOS (v. 8) shim-15.4-2.el8_1, shim-aa64-15.4-2.el8_1, shim-ia32-15.4-2.el8_1 +1
  • RHSA-2021:0701 Released 2021-03-02 · Red Hat rating Moderate
    grub2 security update
    • Red Hat Enterprise Linux ComputeNode EUS (v. 7.6) grub2-1:2.02-0.86.el7_6.3, grub2-common-1:2.02-0.86.el7_6.3, grub2-efi-ia32-1:2.02-0.86.el7_6.3 +8
    • Red Hat Enterprise Linux ComputeNode Optional EUS (v. 7.6) grub2-efi-aa64-modules-1:2.02-0.86.el7_6.3, grub2-efi-ia32-cdboot-1:2.02-0.86.el7_6.3, grub2-efi-x64-cdboot-1:2.02-0.86.el7_6.3 +3
    • Red Hat Enterprise Linux Server EUS (v. 7.6) grub2-1:2.02-0.86.el7_6.3, grub2-common-1:2.02-0.86.el7_6.3, grub2-efi-ia32-1:2.02-0.86.el7_6.3 +12
    • Red Hat Enterprise Linux Server Optional EUS (v. 7.6) grub2-efi-aa64-modules-1:2.02-0.86.el7_6.3, grub2-efi-ia32-cdboot-1:2.02-0.86.el7_6.3, grub2-efi-ia32-modules-1:2.02-0.86.el7_6.3 +6
    • Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server (v. 7) grub2-1:2.02-0.86.el7_6.3, grub2-common-1:2.02-0.86.el7_6.3, grub2-ppc64le-1:2.02-0.86.el7_6.3 +4
    • Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server Optional (v. 7) grub2-efi-aa64-modules-1:2.02-0.86.el7_6.3, grub2-efi-ia32-modules-1:2.02-0.86.el7_6.3, grub2-efi-x64-modules-1:2.02-0.86.el7_6.3 +3
  • RHSA-2021:0700 Released 2021-03-02 · Red Hat rating Moderate
    grub2 security update
    • Red Hat Enterprise Linux ComputeNode EUS (v. 7.7) grub2-1:2.02-0.86.el7_7.3, grub2-common-1:2.02-0.86.el7_7.3, grub2-efi-ia32-1:2.02-0.86.el7_7.3 +8
    • Red Hat Enterprise Linux ComputeNode Optional EUS (v. 7.7) grub2-efi-aa64-modules-1:2.02-0.86.el7_7.3, grub2-efi-ia32-cdboot-1:2.02-0.86.el7_7.3, grub2-efi-x64-cdboot-1:2.02-0.86.el7_7.3 +3
    • Red Hat Enterprise Linux Server EUS (v. 7.7) grub2-1:2.02-0.86.el7_7.3, grub2-common-1:2.02-0.86.el7_7.3, grub2-efi-ia32-1:2.02-0.86.el7_7.3 +12
    • Red Hat Enterprise Linux Server Optional EUS (v. 7.7) grub2-efi-aa64-modules-1:2.02-0.86.el7_7.3, grub2-efi-ia32-cdboot-1:2.02-0.86.el7_7.3, grub2-efi-ia32-modules-1:2.02-0.86.el7_7.3 +6
  • RHSA-2021:0699 Released 2021-03-02 · Red Hat rating Moderate
    grub2 security update
    • Red Hat Enterprise Linux Client (v. 7) grub2-1:2.02-0.87.el7_9.2, grub2-common-1:2.02-0.87.el7_9.2, grub2-efi-ia32-1:2.02-0.87.el7_9.2 +8
    • Red Hat Enterprise Linux Client Optional (v. 7) grub2-efi-aa64-modules-1:2.02-0.87.el7_9.2, grub2-efi-ia32-cdboot-1:2.02-0.87.el7_9.2, grub2-efi-x64-cdboot-1:2.02-0.87.el7_9.2 +3
    • Red Hat Enterprise Linux ComputeNode Optional (v. 7) grub2-efi-aa64-modules-1:2.02-0.87.el7_9.2, grub2-efi-ia32-cdboot-1:2.02-0.87.el7_9.2, grub2-efi-x64-cdboot-1:2.02-0.87.el7_9.2 +3
    • Red Hat Enterprise Linux Server (v. 7) grub2-1:2.02-0.87.el7_9.2, grub2-common-1:2.02-0.87.el7_9.2, grub2-efi-ia32-1:2.02-0.87.el7_9.2 +12
    • Red Hat Enterprise Linux Server Optional (v. 7) grub2-efi-aa64-modules-1:2.02-0.87.el7_9.2, grub2-efi-ia32-cdboot-1:2.02-0.87.el7_9.2, grub2-efi-ia32-modules-1:2.02-0.87.el7_9.2 +6
    • Red Hat Enterprise Linux Workstation (v. 7) grub2-1:2.02-0.87.el7_9.2, grub2-common-1:2.02-0.87.el7_9.2, grub2-efi-ia32-1:2.02-0.87.el7_9.2 +8
    • Red Hat Enterprise Linux Workstation Optional (v. 7) grub2-efi-aa64-modules-1:2.02-0.87.el7_9.2, grub2-efi-ia32-cdboot-1:2.02-0.87.el7_9.2, grub2-efi-x64-cdboot-1:2.02-0.87.el7_9.2 +3
  • RHSA-2021:0702 Released 2021-03-02 · Red Hat rating Moderate
    grub2 security update
    • Red Hat Enterprise Linux Server AUS (v. 7.4) grub2-1:2.02-0.86.el7_4.2, grub2-common-1:2.02-0.86.el7_4.2, grub2-efi-ia32-1:2.02-0.86.el7_4.2 +8
    • Red Hat Enterprise Linux Server E4S (v. 7.4) grub2-1:2.02-0.86.el7_4.2, grub2-common-1:2.02-0.86.el7_4.2, grub2-efi-ia32-1:2.02-0.86.el7_4.2 +10
    • Red Hat Enterprise Linux Server Optional AUS (v. 7.4) grub2-efi-aa64-modules-1:2.02-0.86.el7_4.2, grub2-efi-ia32-cdboot-1:2.02-0.86.el7_4.2, grub2-efi-x64-cdboot-1:2.02-0.86.el7_4.2 +3
    • Red Hat Enterprise Linux Server Optional E4S (v. 7.4) grub2-efi-aa64-modules-1:2.02-0.86.el7_4.2, grub2-efi-ia32-cdboot-1:2.02-0.86.el7_4.2, grub2-efi-ia32-modules-1:2.02-0.86.el7_4.2 +6
    • Red Hat Enterprise Linux Server Optional TUS (v. 7.4) grub2-efi-aa64-modules-1:2.02-0.86.el7_4.2, grub2-efi-ia32-cdboot-1:2.02-0.86.el7_4.2, grub2-efi-x64-cdboot-1:2.02-0.86.el7_4.2 +3
    • Red Hat Enterprise Linux Server TUS (v. 7.4) grub2-1:2.02-0.86.el7_4.2, grub2-common-1:2.02-0.86.el7_4.2, grub2-efi-ia32-1:2.02-0.86.el7_4.2 +8
  • RHSA-2021:0704 Released 2021-03-02 · Red Hat rating Moderate
    grub2 security update
    • Red Hat Enterprise Linux Server AUS (v. 7.2) grub2-1:2.02-0.86.el7_2.2, grub2-common-1:2.02-0.86.el7_2.2, grub2-efi-ia32-1:2.02-0.86.el7_2.2 +10
    • Red Hat Enterprise Linux Server Optional AUS (v. 7.2) grub2-1:2.02-0.86.el7_2.2, grub2-efi-aa64-modules-1:2.02-0.86.el7_2.2, grub2-efi-ia32-cdboot-1:2.02-0.86.el7_2.2 +7
  • RHSA-2021:0703 Released 2021-03-02 · Red Hat rating Moderate
    grub2 security update
    • Red Hat Enterprise Linux Server AUS (v. 7.3) grub2-1:2.02-0.86.el7_3.2, grub2-common-1:2.02-0.86.el7_3.2, grub2-efi-ia32-1:2.02-0.86.el7_3.2 +11
    • Red Hat Enterprise Linux Server Optional AUS (v. 7.3) grub2-1:2.02-0.86.el7_3.2, grub2-common-1:2.02-0.86.el7_3.2, grub2-efi-aa64-modules-1:2.02-0.86.el7_3.2 +14
  • RHSA-2021:0697 Released 2021-03-02 · Red Hat rating Moderate
    grub2 security update
    • Red Hat Enterprise Linux BaseOS EUS (v. 8.2) grub2-1:2.02-87.el8_2.3, grub2-common-1:2.02-87.el8_2.3, grub2-efi-aa64-1:2.02-87.el8_2.3 +16
  • RHSA-2021:0696 Released 2021-03-02 · Red Hat rating Moderate
    grub2 security update
    • Red Hat Enterprise Linux BaseOS (v. 8) grub2-1:2.02-90.el8_3.1, grub2-common-1:2.02-90.el8_3.1, grub2-efi-aa64-1:2.02-90.el8_3.1 +16
  • RHSA-2021:0698 Released 2021-03-02 · Red Hat rating Moderate
    grub2 security update
    • Red Hat Enterprise Linux BaseOS EUS (v. 8.1) grub2-1:2.02-87.el8_1.2, grub2-common-1:2.02-87.el8_1.2, grub2-efi-aa64-1:2.02-87.el8_1.2 +16

Microsoft 1 update

  • ADV200011 Released 2020-07-29
    Microsoft Guidance for Addressing Security Feature Bypass in GRUB

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Advisory ·

    grub2 — FEDORA-2021-cab258a413

    7 records Highest priority Priority LOW 7 LOW

    Other records, highest priority first

    • TI-2020-15650 Use after free in grub2Priority LOW 38
    • TI-2021-03528 Out-of-bounds write in grub2Priority LOW 37
    • TI-2020-11240 A flaw was found in grub2 in versions prior to 2.06, where it incorrectly enables the…Priority LOW 36
    Show all 7 records → Advisory →

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 7AffectedNo fix yet
Red Hat CodeReady Linux Builder (v. 8)Fixed RHSA-2021:1734
Red Hat CodeReady Linux Builder EUS (v. 8.1)Fixed RHSA-2021:3675
Red Hat CodeReady Linux Builder EUS (v. 8.2)Fixed RHSA-2021:2790
Red Hat Enterprise Linux BaseOS (v. 8)Fixed RHSA-2021:0696, RHSA-2021:1734, RHSA-2021:2566
Red Hat Enterprise Linux BaseOS EUS (v. 8.1)Fixed RHSA-2021:0698, RHSA-2021:3675
Red Hat Enterprise Linux BaseOS EUS (v. 8.2)Fixed RHSA-2021:0697, RHSA-2021:2790
Red Hat Enterprise Linux Client (v. 7)Fixed RHSA-2021:0699
Red Hat Enterprise Linux Client Optional (v. 7)Fixed RHSA-2021:0699
Red Hat Enterprise Linux ComputeNode EUS (v. 7.6)Fixed RHSA-2021:0701
Red Hat Enterprise Linux ComputeNode EUS (v. 7.7)Fixed RHSA-2021:0700
Red Hat Enterprise Linux ComputeNode Optional (v. 7)Fixed RHSA-2021:0699
Red Hat Enterprise Linux ComputeNode Optional EUS (v. 7.6)Fixed RHSA-2021:0701
Red Hat Enterprise Linux ComputeNode Optional EUS (v. 7.7)Fixed RHSA-2021:0700
Red Hat Enterprise Linux Server (v. 7)Fixed RHSA-2021:0699
Red Hat Enterprise Linux Server AUS (v. 7.2)Fixed RHSA-2021:0704
Red Hat Enterprise Linux Server AUS (v. 7.3)Fixed RHSA-2021:0703
Red Hat Enterprise Linux Server AUS (v. 7.4)Fixed RHSA-2021:0702
Red Hat Enterprise Linux Server E4S (v. 7.4)Fixed RHSA-2021:0702
Red Hat Enterprise Linux Server EUS (v. 7.6)Fixed RHSA-2021:0701
Red Hat Enterprise Linux Server EUS (v. 7.7)Fixed RHSA-2021:0700
Red Hat Enterprise Linux Server Optional (v. 7)Fixed RHSA-2021:0699
Red Hat Enterprise Linux Server Optional AUS (v. 7.2)Fixed RHSA-2021:0704
Red Hat Enterprise Linux Server Optional AUS (v. 7.3)Fixed RHSA-2021:0703
Red Hat Enterprise Linux Server Optional AUS (v. 7.4)Fixed RHSA-2021:0702
Red Hat Enterprise Linux Server Optional E4S (v. 7.4)Fixed RHSA-2021:0702
Red Hat Enterprise Linux Server Optional EUS (v. 7.6)Fixed RHSA-2021:0701
Red Hat Enterprise Linux Server Optional EUS (v. 7.7)Fixed RHSA-2021:0700
Red Hat Enterprise Linux Server Optional TUS (v. 7.4)Fixed RHSA-2021:0702
Red Hat Enterprise Linux Server TUS (v. 7.4)Fixed RHSA-2021:0702
Red Hat Enterprise Linux Workstation (v. 7)Fixed RHSA-2021:0699
Red Hat Enterprise Linux Workstation Optional (v. 7)Fixed RHSA-2021:0699
Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server (v. 7)Fixed RHSA-2021:0701
Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server Optional (v. 7)Fixed RHSA-2021:0701
Not affected: 1 product
  • Red Hat Enterprise Linux 7

Timeline

  1. 2026-10-02 Threatist record created from CVE-2020-27779
  2. 2026-10-03 Alias added: GHSA-7p29-8vr2-rmvx

References

Advisory 4

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences