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Vulnerability · Published Mar 15, 2021 · Assigned by redhat

CVE-2021-3418

Medium 6.4

In plain English

A medium-severity security flaw in grub2. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 41% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)6.4Medium
Exploit odds (30 days)0.5%top 59.5% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Alpine:v3.20grub2.06-r0ALPINE-CVE-2021-3418
Alpine:v3.21grub2.06-r0ALPINE-CVE-2021-3418
Alpine:v3.22grub2.06-r0ALPINE-CVE-2021-3418
Alpine:v3.23grub2.06-r0ALPINE-CVE-2021-3418
Alpine:v3.24grub2.06-r0ALPINE-CVE-2021-3418

Affected products (as reported)

VendorProductVersions
n/a grub2 Fixed in 2.06

Weakness: CWE-281

References