medium
6.4
CWE
347 440
Advisory Published
CVE Published
CVE Published
Updated

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

First published: Mon Jul 27 2020(Updated: )

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.

Credit: security@ubuntu.com

Affected SoftwareAffected VersionHow to fix
redhat/fwupdate<0:12-6.el7_8
0:12-6.el7_8
redhat/grub2<1:2.02-0.86.el7_8
1:2.02-0.86.el7_8
redhat/shim<0:15-7.el7_9
0:15-7.el7_9
redhat/shim-signed<0:15-7.el7_8
0:15-7.el7_8
redhat/grub2<1:2.02-0.86.el7_2
1:2.02-0.86.el7_2
redhat/shim<0:15-8.el7
0:15-8.el7
redhat/shim-signed<0:15-8.el7_2
0:15-8.el7_2
redhat/grub2<1:2.02-0.86.el7
1:2.02-0.86.el7
redhat/shim-signed<0:15-8.el7_3
0:15-8.el7_3
redhat/fwupdate<0:9-10.el7_4
0:9-10.el7_4
redhat/grub2<1:2.02-0.86.el7_4
1:2.02-0.86.el7_4
redhat/shim-signed<0:15-8.el7_4
0:15-8.el7_4
redhat/fwupdate<0:12-6.el7_6
0:12-6.el7_6
redhat/grub2<1:2.02-0.86.el7_6
1:2.02-0.86.el7_6
redhat/shim-signed<0:15-8.el7_6
0:15-8.el7_6
redhat/fwupdate<0:12-6.el7_7
0:12-6.el7_7
redhat/grub2<1:2.02-0.86.el7_7
1:2.02-0.86.el7_7
redhat/shim-signed<0:15-8.el7_7
0:15-8.el7_7
redhat/fwupd<0:1.1.4-7.el8_2
0:1.1.4-7.el8_2
redhat/grub2<1:2.02-87.el8_2
1:2.02-87.el8_2
redhat/shim<0:15-14.el8_2
0:15-14.el8_2
redhat/shim-unsigned-x64<0:15-7.el8
0:15-7.el8
redhat/fwupd<0:1.1.4-2.el8_0
0:1.1.4-2.el8_0
redhat/grub2<1:2.02-87.el8_0
1:2.02-87.el8_0
redhat/shim<0:15-14.el8_0
0:15-14.el8_0
redhat/fwupd<0:1.1.4-2.el8_1
0:1.1.4-2.el8_1
redhat/grub2<1:2.02-87.el8_1
1:2.02-87.el8_1
redhat/shim<0:15-14.el8_1
0:15-14.el8_1
redhat/grub<2.06
2.06
debian/grub2
2.06-3~deb11u6
2.06-13+deb12u1
2.12-5
GRUB 2<=2.04
Red Hat Enterprise Linux Atomic Host
redhat openshift container platform=4.0
Ubuntu Linux=14.04
Ubuntu Linux=16.04
Ubuntu Linux=18.04
Ubuntu Linux=20.04
Debian GNU/Linux=10.0
openSUSE=15.1
openSUSE=15.2
Red Hat Enterprise Linux=7.0
Red Hat Enterprise Linux=8.0
SUSE Linux Enterprise Server=11
SUSE Linux Enterprise Server=12
SUSE Linux Enterprise Server=15
Microsoft Windows 10
Microsoft Windows 10=1607
Microsoft Windows 10=1709
Microsoft Windows 10=1803
Microsoft Windows 10=1809
Microsoft Windows 10=1903
Microsoft Windows 10=1909
Microsoft Windows 10=2004
Microsoft Windows 8.1
Microsoft Windows RT
Microsoft Windows Server 2012 x64
Microsoft Windows Server 2012 x64=r2
Microsoft Windows Server 2016
Microsoft Windows Server 2016=1903
Microsoft Windows Server 2016=1909
Microsoft Windows Server 2016=2004
Microsoft Windows Server 2019
Ubuntu=14.04
Ubuntu=16.04
Ubuntu=18.04
Ubuntu=20.04
Debian=10.0

Remedy

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/ADV200011

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Reference Links

Parent vulnerabilities

(Appears in the following advisories)

Frequently Asked Questions

  • What is the vulnerability ID for this issue?

    The vulnerability ID for this issue is CVE-2020-15705.

  • What is the severity of CVE-2020-15705?

    The severity of CVE-2020-15705 is medium (6.4).

  • Which systems are affected by this vulnerability?

    This vulnerability 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.

  • How can this vulnerability be exploited?

    This vulnerability allows secure boot to be bypassed by failing to validate kernel signature when booted directly without shim.

  • Where can I find more information about CVE-2020-15705?

    You can find more information about CVE-2020-15705 on the Red Hat website (https://access.redhat.com/security/cve/cve-2020-15705).

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