Grub2
CVE-2021-3418
MEDIUM
Severity by source
AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
Lifecycle Timeline
1DescriptionNVD
If certificates that signed grub are installed into db, grub can be booted directly. It will then boot any kernel without signature validation. The booted kernel will think it was booted in secureboot mode and will implement lockdown, yet it could have been tampered. This flaw is a reintroduction of CVE-2020-15705 and only affects grub2 versions prior to 2.06 and upstream and distributions using the shim_lock mechanism.
AnalysisAI
If certificates that signed grub are installed into db, grub can be booted directly. Rated medium severity (CVSS 6.4). No vendor patch available.
Technical ContextAI
This vulnerability is classified under CWE-281. If certificates that signed grub are installed into db, grub can be booted directly. It will then boot any kernel without signature validation. The booted kernel will think it was booted in secureboot mode and will implement lockdown, yet it could have been tampered. This flaw is a reintroduction of CVE-2020-15705 and only affects grub2 versions prior to 2.06 and upstream and distributions using the shim_lock mechanism. Affected products include: Gnu Grub2. Version information: prior to 2.06.
RemediationAI
No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.
Multiple integer underflows in Grub2 1.98 through 2.02 allow physically proximate attackers to bypass authentication, ob
An out-of-bounds write flaw was found in grub2's NTFS filesystem driver. Rated high severity (CVSS 7.8), this vulnerabil
GRUB2 does not call the module fini functions on exit, leading to Debian/Ubuntu's peimage GRUB2 module leaving UEFI syst
Integer overflows were discovered in the functions grub_cmd_initrd and grub_initrd_init in the efilinux component of GRU
GNU GRUB (aka GRUB2) through 2.12 has a heap-based buffer overflow in fs/hfs.c via crafted sblock data in an HFS filesys
A buffer overflow was found in grub_font_construct_glyph(). Rated high severity (CVSS 8.6), this vulnerability is no aut
An out-of-bounds read flaw was found on grub2's NTFS filesystem driver. Rated medium severity (CVSS 4.6), this vulnerabi
A flaw was found in grub2 in versions prior to 2.06. Rated high severity (CVSS 8.2), this vulnerability is low attack co
A flaw was found in grub2, prior to version 2.06. Rated high severity (CVSS 8.2), this vulnerability is low attack compl
A flaw was found in grub2. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch
A flaw was found in the HFS filesystem. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No
When reading data from a hfs filesystem, grub's hfs filesystem module uses user-controlled parameters from the filesyste
Same weakness CWE-281 – Improper Preservation of Permissions
View allSame technique Information Disclosure
View allShare
External POC / Exploit Code
Leaving vuln.today