GRUB2 contained integer overflows when handling the initrd command, leading to a heap-based buffer overflow.
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 5.7epss 1.6%
exploitation probability
1.6%top 27% of all CVEs
observed exploitation
nono source reports it
Integer overflows were discovered in the functions grub_cmd_initrd and grub_initrd_init in the efilinux component of GRUB2, as shipped in Debian, Red Hat, and Ubuntu (the functionality is not included in GRUB2 upstream), leading to a heap-based buffer overflow. These could be triggered by an extremely large number of arguments to the initrd command on 32-bit architectures, or a crafted filesystem with very large files on any architecture. An attacker could use this to execute arbitrary code and bypass UEFI Secure Boot restrictions. This issue affects GRUB2 version 2.04 and prior versions.
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:H
Affected products
Ubuntu · grub2 in UbuntuReferences
http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00016.htmlhttp://lists.opensuse.org/opensuse-security-announce/2020-08/msg00017.htmlhttps://access.redhat.com/security/vulnerabilities/grub2bootloaderhttps://lists.gnu.org/archive/html/grub-devel/2020-07/msg00034.htmlhttps://portal.msrc.microsoft.com/en-US/security-guidance/advisory/ADV200011https://security.gentoo.org/glsa/202104-05https://security.netapp.com/advisory/ntap-20200731-0008/https://usn.ubuntu.com/4432-1/https://wiki.ubuntu.com/SecurityTeam/KnowledgeBase/GRUB2SecureBootBypasshttps://www.debian.org/security/2020/dsa-4735https://www.debian.org/security/2020-GRUB-UEFI-SecureBoothttps://www.eclypsium.com/2020/07/29/theres-a-hole-in-the-boot/