CVE-2021-3418
"Grub Secure Boot Certificate Validation Bypass"
Description
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.
INFO
Published Date :
March 15, 2021, 10:15 p.m.
Last Modified :
March 22, 2021, 4:45 p.m.
Source :
[email protected]
Remotely Exploitable :
No
Impact Score :
5.9
Exploitability Score :
0.5
Public PoC/Exploit Available at Github
CVE-2021-3418 has a 23 public PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2021-3418.
| URL | Resource |
|---|---|
| https://bugzilla.redhat.com/show_bug.cgi?id=1933757 | Issue Tracking Third Party Advisory |
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
shim-review but not forked to be able to use LFS
Dockerfile Shell
None
Dockerfile
None
Dockerfile Makefile
None
Dockerfile
None
None
Dockerfile Shell
None
Dockerfile
Repository for all information needed for shim-review
Dockerfile
shim-review for Navix
Dockerfile
None
None
Dockerfile Makefile
None
Dockerfile
None
Dockerfile
None
None
PowerShell
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2021-3418 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-3418 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by [email protected]
May. 14, 2024
Action Type Old Value New Value -
Initial Analysis by [email protected]
Mar. 22, 2021
Action Type Old Value New Value Added CVSS V2 NIST (AV:L/AC:M/Au:N/C:P/I:P/A:P) Added CVSS V3.1 NIST AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H Changed Reference Type https://bugzilla.redhat.com/show_bug.cgi?id=1933757 No Types Assigned https://bugzilla.redhat.com/show_bug.cgi?id=1933757 Issue Tracking, Third Party Advisory Added CPE Configuration OR *cpe:2.3:a:gnu:grub2:*:*:*:*:*:*:*:* versions up to (excluding) 2.06 -
CVE Modified by [email protected]
Mar. 18, 2021
Action Type Old Value New Value Changed Description 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 grbu2 versions prior to 2.06 and upstream and distributions using the shim_lock mechanism. 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.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-3418 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2021-3418
weaknesses.
Exploit Prediction
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.
0.04 }} 0.00%
score
0.10264
percentile