Race condition in grub - CVE-2020-15706

Vulnerability identifier: #VU32926

CSH Severity: Low

CVSS v4: 7 [CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2020-15706

CWE-ID: CWE-362

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local attacker to execute arbitrary code and bypass secure boot restriction.

The vulnerability exists due to a race condition in the "grub_script_function_create()" function. An attacker with physical access can exploit the race and execute arbitrary code on the target system.

grub
Debian Linux
Gentoo Linux
CentOS
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for Scientific Computing
Red Hat Enterprise Linux for Power, big endian
Red Hat Enterprise Linux Desktop
Red Hat Enterprise Linux Workstation
Red Hat Enterprise Linux Server
Red Hat Enterprise Linux Server - AUS
Red Hat CodeReady Linux Builder for x86_64
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for x86_64
Anolis OS
Red Hat Enterprise Linux for IBM z Systems - Extended Update Support
Red Hat Enterprise Linux for x86_64 - Extended Update Support
Red Hat Enterprise Linux for Power, little endian - Extended Update Support
Red Hat Enterprise Linux Server - TUS
Ubuntu
Opensuse
openEuler
APM Edge
Data Computing Appliance (DCA)
fwupd (Red Hat package)
grub2 (Red Hat package)
Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions
Red Hat Enterprise Linux Server for x86_64 - Update Services for SAP Solutions
shim-signed (Red Hat package)
shim (Red Hat package)
fwupd
grub-efi-amd64-signed (Ubuntu package)
grub-efi-arm64-signed (Ubuntu package)
grub-efi-ia32-bin (Ubuntu package)
grub-efi-arm64-bin (Ubuntu package)
grub-efi-arm-bin (Ubuntu package)
grub-efi-amd64-bin (Ubuntu package)
grub2 (Debian package)
grub2-debuginfo
grub2
grub2-common
grub2-tools-efi
grub2-pc
grub2-efi-x64-cdboot
grub2-efi-x64
grub2-efi-ia32-cdboot
grub2-efi-ia32
grub2-tools
grub2-help
grub2-efi-aa64-modules
grub2-efi-aa64-cdboot
grub2-efi-aa64
grub2-debugsource
fwupdate (Red Hat package)
shim-unsigned-x64 (Red Hat package)
IBM Security Guardium

Install updates from vendor's website.

grub - update to 2.05
APM Edge - update to 4.0
fwupd (Red Hat package) - addressed in versions 1.1.4-2.el8_1, 1.1.4-7.el8_2
grub2 (Red Hat package) - addressed in versions 2.02-0.86.el7_2, 2.02-0.86.el7_7, 2.02-0.86.el7_8, 2.02-87.el8_1, 2.02-87.el8_2
shim-signed (Red Hat package) - addressed in versions 15-7.el7_8, 15-8.el7_2, 15-8.el7_7
shim (Red Hat package) - addressed in versions 15-7.el7_9, 15-8.el7, 15-14.el8_1, 15-14.el8_2
fwupd - update to 1.1.4-7.0.1
grub-efi-amd64-signed (Ubuntu package) - addressed in versions 1.66.26+2.02~beta2-36ubuntu3.26, 1.66.27+2.02~beta2-36ubuntu3.27, 1.93.18+2.02-2ubuntu8.16, 1.93.19+2.02-2ubuntu8.17, 1.142.3+2.04-1ubuntu26.1, 1.142.4+2.04-1ubuntu26.2
grub-efi-arm64-signed (Ubuntu package) - addressed in versions 1.66.26+2.02~beta2-36ubuntu3.26, 1.66.27+2.02~beta2-36ubuntu3.27, 1.93.18+2.02-2ubuntu8.16, 1.93.19+2.02-2ubuntu8.17, 1.142.3+2.04-1ubuntu26.1, 1.142.4+2.04-1ubuntu26.2
grub-efi-ia32-bin (Ubuntu package) - addressed in versions 2.02~beta2-36ubuntu3.26, 2.02~beta2-36ubuntu3.27, 2.02-2ubuntu8.16, 2.02-2ubuntu8.17, 2.04-1ubuntu26.1, 2.04-1ubuntu26.2
grub-efi-arm64-bin (Ubuntu package) - addressed in versions 2.02~beta2-36ubuntu3.26, 2.02~beta2-36ubuntu3.27, 2.02-2ubuntu8.16, 2.02-2ubuntu8.17, 2.04-1ubuntu26.1, 2.04-1ubuntu26.2
grub-efi-arm-bin (Ubuntu package) - addressed in versions 2.02~beta2-36ubuntu3.26, 2.02~beta2-36ubuntu3.27, 2.02-2ubuntu8.16, 2.02-2ubuntu8.17, 2.04-1ubuntu26.1, 2.04-1ubuntu26.2
grub-efi-amd64-bin (Ubuntu package) - addressed in versions 2.02~beta2-36ubuntu3.26, 2.02~beta2-36ubuntu3.27, 2.02-2ubuntu8.16, 2.02-2ubuntu8.17, 2.04-1ubuntu26.1, 2.04-1ubuntu26.2
grub2 (Debian package) - update to 2.02+dfsg1-20+deb10u1
grub2-debuginfo - update to 2.02-77
grub2 - update to 2.02-77
grub2-common - update to 2.02-77
grub2-tools-efi - update to 2.02-77
grub2-pc - update to 2.02-77
grub2-efi-x64-cdboot - update to 2.02-77
grub2-efi-x64 - update to 2.02-77
grub2-efi-ia32-cdboot - update to 2.02-77
grub2-efi-ia32 - update to 2.02-77
grub2-tools - update to 2.02-77
grub2-help - update to 2.02-77
grub2-efi-aa64-modules - update to 2.02-77
grub2-efi-aa64-cdboot - update to 2.02-77
grub2-efi-aa64 - update to 2.02-77
grub2-debugsource - update to 2.02-77
Data Computing Appliance (DCA) - update to 4.3.0.0
fwupdate (Red Hat package) - addressed in versions 12-6.el7_7, 12-6.el7_8
shim-unsigned-x64 (Red Hat package) - update to 15-7.el8

• http://ubuntu.com/security/notices/USN-4432-1
• http://www.openwall.com/lists/oss-security/2020/07/29/3
• https://access.redhat.com/security/vulnerabilities/grub2bootloader
• https://lists.gnu.org/archive/html/grub-devel/2020-07/msg00034.html
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/ADV200011
• https://wiki.ubuntu.com/SecurityTeam/KnowledgeBase/GRUB2SecureBootBypass
• https://www.debian.org/security/2020/dsa-4735
• https://www.debian.org/security/2020-GRUB-UEFI-SecureBoot
• https://www.eclypsium.com/2020/07/29/theres-a-hole-in-the-boot/
• https://www.openwall.com/lists/oss-security/2020/07/29/3
• https://www.suse.com/c/suse-addresses-grub2-secure-boot-issue/
• https://www.suse.com/support/kb/doc/?id=000019673

• Multiple vulnerabilities in GRUB2
• Red Hat 8.1 update for grub2
• Red Hat 7 update for grub2
• Red Hat 8 update for grub2
• CentOS 7 update for grub2
• CentOS 7 update for shim-signed
• CentOS 7 update for shim
• Red Hat 7.7 update for grub2
• Red Hat AUS 7.2 update for grub2
• OpenSUSE Linux update for grub2
• OpenSUSE Linux update for grub2
• Gentoo update for GRUB
• Multiple vulnerabilities in Hitachi Energy APM Edge
• Debian update for grub2
• Multiple vulnerabilities in Dell EMC Data Computing Appliance (DCA)
• Multiple vulnerabilities in IBM Security Guardium
• openEuler 20.03 LTS update for grub2
• Anolis OS update for fwupd
• Ubuntu update for grub2
• Ubuntu update for grub2