Read the docs
TI-2021-02630 Aliases CVE-2021-3695GHSA-xjhh-w3rj-8mxm

Out-of-bounds write in grub2

Priority LOW 21CWE-787Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
High
Impact type
—
Confidentiality · integrity · availability
Low · Low · Low
Fix status
Partial Red Hat: 5 fixed, 1 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat.

Summary

A crafted 16-bit grayscale PNG image may lead to a out-of-bounds write in the heap area. An attacker may take advantage of that to cause heap data corruption or eventually arbitrary code execution and circumvent secure boot protections. This issue has a high complexity to be exploited as an attacker needs to perform some triage over the heap layout to achieve signifcant results, also the values written into the memory are repeated three times in a row making difficult to produce valid payloads. This flaw affects grub2 versions prior grub-2.12.

Why it matters now

EPSS 0.00475 41st percentileScored 2026-11-07
Fix Partial Red Hat: 5 advisoriesRed Hat: 5 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 · 40

CPEVersionsRoleVendor
cpe:2.3:a:gnu:grub2:*:*:*:*:*:*:*:*2.00 to before 2.12VulnerableGNU
cpe:2.3:o:fedoraproject:fedora:36:*:*:*:*:*:*:*36VulnerableFedoraproject
cpe:2.3:a:redhat:developer_tools:1.0:*:*:*:*:*:*:*1.0VulnerableRed Hat
cpe:2.3:a:redhat:openshift:3.0:*:*:*:*:*:*:*3.0VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*8.0VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux:8.1:*:*:*:*:*:*:*8.1VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux:8.4:*:*:*:*:*:*:*8.4VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*9.0VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_eus:8.2:*:*:*:*:*:*:*8.2VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_eus:8.4:*:*:*:*:*:*:*8.4VulnerableRed Hat
  • cpe:2.3:a:gnu:grub2:*:*:*:*:*:*:*:* Versions 2.00 to before 2.12 Vulnerable ·GNU
  • cpe:2.3:o:fedoraproject:fedora:36:*:*:*:*:*:*:* Versions 36 Vulnerable ·Fedoraproject
  • cpe:2.3:a:redhat:developer_tools:1.0:*:*:*:*:*:*:* Versions 1.0 Vulnerable ·Red Hat
  • cpe:2.3:a:redhat:openshift:3.0:*:*:*:*:*:*:* Versions 3.0 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:8.1:*:*:*:*:*:*:* Versions 8.1 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux:8.4:*:*:*:*:*:*:* Versions 8.4 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_eus:8.2:*:*:*:*:*:*:* Versions 8.2 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_eus:8.4:*:*:*:*:*:*:* Versions 8.4 Vulnerable ·Red Hat
Show 30 more CPE
CPEVersionsRoleVendor
cpe:2.3:o:redhat:enterprise_linux_eus:8.6:*:*:*:*:*:*:*8.6VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_eus:9.0:*:*:*:*:*:*:*9.0VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:8.0:*:*:*:*:*:*:*8.0VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:9.0:*:*:*:*:*:*:*9.0VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:8.2:*:*:*:*:*:*:*8.2VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:8.4:*:*:*:*:*:*:*8.4VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:8.6:*:*:*:*:*:*:*8.6VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:9.0:*:*:*:*:*:*:*9.0VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_server_aus:8.2:*:*:*:*:*:*:*8.2VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_server_aus:8.4:*:*:*:*:*:*:*8.4VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_server_aus:8.6:*:*:*:*:*:*:*8.6VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:8.1:*:*:*:*:*:*:*8.1VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:8.2:*:*:*:*:*:*:*8.2VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:8.4:*:*:*:*:*:*:*8.4VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:8.6:*:*:*:*:*:*:*8.6VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:9.0:*:*:*:*:*:*:*9.0VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_server_tus:8.2:*:*:*:*:*:*:*8.2VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_server_tus:8.4:*:*:*:*:*:*:*8.4VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_server_tus:8.6:*:*:*:*:*:*:*8.6VulnerableRed Hat
cpe:2.3:a:redhat:openshift_container_platform:4.6:*:*:*:*:*:*:*4.6VulnerableRed Hat
cpe:2.3:a:redhat:openshift_container_platform:4.9:*:*:*:*:*:*:*4.9VulnerableRed Hat
cpe:2.3:a:redhat:openshift_container_platform:4.10:*:*:*:*:*:*:*4.10VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*8.0Running onRed Hat
cpe:2.3:a:redhat:codeready_linux_builder:-:*:*:*:*:*:*:*not specified by NVDVulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*9.0Running onRed Hat
cpe:2.3:o:redhat:enterprise_linux_eus:8.2:*:*:*:*:*:*:*8.2Running onRed Hat
cpe:2.3:o:redhat:enterprise_linux_eus:8.4:*:*:*:*:*:*:*8.4Running onRed Hat
cpe:2.3:o:redhat:enterprise_linux_eus:8.6:*:*:*:*:*:*:*8.6Running onRed Hat
cpe:2.3:o:redhat:enterprise_linux_eus:9.0:*:*:*:*:*:*:*9.0Running onRed Hat
cpe:2.3:a:netapp:ontap_select_deploy_administration_utility:-:*:*:*:*:*:*:*not specified by NVDVulnerableNetApp
  • cpe:2.3:o:redhat:enterprise_linux_eus:8.6:*:*:*:*:*:*:* Versions 8.6 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_eus:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:8.0:*:*:*:*:*:*:* Versions 8.0 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:8.2:*:*:*:*:*:*:* Versions 8.2 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:8.4:*:*:*:*:*:*:* Versions 8.4 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:8.6:*:*:*:*:*:*:* Versions 8.6 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:9.0:*:*:*:*:*:*:* Versions 9.0 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_aus:8.4:*:*:*:*:*:*:* Versions 8.4 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_server_aus:8.6:*:*:*:*:*:*:* Versions 8.6 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:8.1:*:*:*:*:*:*:* Versions 8.1 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:8.2:*:*:*:*:*:*:* Versions 8.2 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:8.4:*:*:*:*:*:*:* Versions 8.4 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:8.6:*:*:*:*:*:*:* Versions 8.6 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:9.0:*:*:*:*:*:*:* Versions 9.0 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_server_tus:8.4:*:*:*:*:*:*:* Versions 8.4 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_server_tus:8.6:*:*:*:*:*:*:* Versions 8.6 Vulnerable ·Red Hat
  • cpe:2.3:a:redhat:openshift_container_platform:4.6:*:*:*:*:*:*:* Versions 4.6 Vulnerable ·Red Hat
  • cpe:2.3:a:redhat:openshift_container_platform:4.9:*:*:*:*:*:*:* Versions 4.9 Vulnerable ·Red Hat
  • cpe:2.3:a:redhat:openshift_container_platform:4.10:*:*:*:*:*:*:* Versions 4.10 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* Versions 8.0 Running on ·Red Hat
  • cpe:2.3:a:redhat:codeready_linux_builder:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Running on ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_eus:8.2:*:*:*:*:*:*:* Versions 8.2 Running on ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_eus:8.4:*:*:*:*:*:*:* Versions 8.4 Running on ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_eus:8.6:*:*:*:*:*:*:* Versions 8.6 Running on ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_eus:9.0:*:*:*:*:*:*:* Versions 9.0 Running on ·Red Hat
  • cpe:2.3:a:netapp:ontap_select_deploy_administration_utility:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp

Remediation

Red Hat 5 advisories

  • RHSA-2022:5100 Released 2022-06-16 · Red Hat rating Important
    grub2, mokutil, shim, and shim-unsigned-x64 security update
    • Red Hat CodeReady Linux Builder EUS (v. 8.2) shim-unsigned-x64-15.6-1.el8
    • Red Hat Enterprise Linux BaseOS EUS (v. 8.2) grub2-1:2.02-87.el8_2.10, grub2-common-1:2.02-87.el8_2.10, grub2-efi-aa64-1:2.02-87.el8_2.10 +20
  • RHSA-2022:5095 Released 2022-06-16 · Red Hat rating Important
    grub2, mokutil, shim, and shim-unsigned-x64 security update
    • Red Hat Enterprise Linux BaseOS (v. 8) grub2-1:2.02-123.el8_6.8, grub2-common-1:2.02-123.el8_6.8, grub2-efi-aa64-1:2.02-123.el8_6.8 +20
    • Red Hat Enterprise Linux CRB (v. 8) shim-unsigned-x64-15.6-1.el8
  • RHSA-2022:5099 Released 2022-06-16 · Red Hat rating Important
    grub2, mokutil, shim, and shim-unsigned-x64 security update
    • Red Hat CodeReady Linux Builder (v. 9) shim-unsigned-x64-15.6-1.el9
    • Red Hat Enterprise Linux BaseOS (v. 9) grub2-1:2.06-27.el9_0.7, grub2-common-1:2.06-27.el9_0.7, grub2-efi-aa64-1:2.06-27.el9_0.7 +16
Show 2 more Red Hat advisories
  • RHSA-2022:5096 Released 2022-06-16 · Red Hat rating Important
    grub2, mokutil, shim, and shim-unsigned-x64 security update
    • Red Hat Enterprise Linux BaseOS EUS (v.8.4) grub2-1:2.02-99.el8_4.9, grub2-common-1:2.02-99.el8_4.9, grub2-efi-aa64-1:2.02-99.el8_4.9 +20
    • Red Hat Enterprise Linux CRB EUS (v.8.4) shim-unsigned-x64-15.6-1.el8
  • RHSA-2022:5098 Released 2022-06-16 · Red Hat rating Important
    grub2, mokutil, and shim security update
    • Red Hat Enterprise Linux BaseOS E4S (v. 8.1) grub2-1:2.02-87.el8_1.10, grub2-common-1:2.02-87.el8_1.10, grub2-efi-aa64-modules-1:2.02-87.el8_1.10 +17

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat Enterprise Linux 7AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux BaseOS (v. 8)Fixed RHSA-2022:5095
Red Hat Enterprise Linux BaseOS (v. 9)Fixed RHSA-2022:5099
Red Hat Enterprise Linux BaseOS E4S (v. 8.1)Fixed RHSA-2022:5098
Red Hat Enterprise Linux BaseOS EUS (v. 8.2)Fixed RHSA-2022:5100
Red Hat Enterprise Linux BaseOS EUS (v.8.4)Fixed RHSA-2022:5096
Not affected: 9 products
  • Red Hat CodeReady Linux Builder (v. 9)
  • Red Hat CodeReady Linux Builder EUS (v. 8.2)
  • Red Hat Enterprise Linux BaseOS (v. 8)
  • Red Hat Enterprise Linux BaseOS (v. 9)
  • Red Hat Enterprise Linux BaseOS E4S (v. 8.1)
  • Red Hat Enterprise Linux BaseOS EUS (v. 8.2)
  • Red Hat Enterprise Linux BaseOS EUS (v.8.4)
  • Red Hat Enterprise Linux CRB (v. 8)
  • Red Hat Enterprise Linux CRB EUS (v.8.4)

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-3695
  2. 2026-10-03 Alias added: GHSA-xjhh-w3rj-8mxm

References

Advisory 3

Sources

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