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Vulnerability · Published Mar 3, 2021 · Assigned by redhat

CVE-2020-27779

High 7.5

In plain English

A high-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 0.4% (higher than 33% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)7.5High
Exploit odds (30 days)0.4%top 66.6% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

Official description

A flaw was found in grub2 in versions prior to 2.06. The cutmem command does not honor secure boot locking allowing an privileged attacker to remove address ranges from memory creating an opportunity to circumvent SecureBoot protections after proper triage about grub's memory layout. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
AlmaLinux:8shim-aa6415.4-2.el8_1.almaALSA-2021:1734
AlmaLinux:8shim-ia3215.4-2.el8_1.almaALSA-2021:1734
AlmaLinux:8shim-unsigned-aarch6415-7.el8_1.almaALSA-2021:1734
AlmaLinux:8shim-unsigned-x6415.4-4.el8_1.almaALSA-2021:1734
AlmaLinux:8shim-x6415.4-2.el8_1.almaALSA-2021:1734
Alpine:v3.20grub2.06-r0ALPINE-CVE-2020-27779
Alpine:v3.21grub2.06-r0ALPINE-CVE-2020-27779
Alpine:v3.22grub2.06-r0ALPINE-CVE-2020-27779
Alpine:v3.23grub2.06-r0ALPINE-CVE-2020-27779
Alpine:v3.24grub2.06-r0ALPINE-CVE-2020-27779
Debian:12grub22.04-16DEBIAN-CVE-2020-27779
Debian:13grub22.04-16DEBIAN-CVE-2020-27779
Debian:14grub22.04-16DEBIAN-CVE-2020-27779
Rocky Linux:8fwupd0:1.5.9-1.el8_4RLSA-2021:2566
Rocky Linux:8shim-unsigned-aarch640:15-7.el8.1.1RLSA-2021:1734

Affected products (as reported)

VendorProductVersions
n/a grub2 grub 2.06

Weakness: CWE-285

References