What’s Vulnerable › Vulnerabilities

CVE-2020-27779

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-03-03 · updated 2026-06-17
• Weakness: CWE-285

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 products

• Fedoraproject Fedora: 33, 34
• grub2: before 2.06 — fixed in 2.06
• NetApp ONTAP Select Deploy administration utility: all versions
• Red Hat Enterprise Linux: 7.0, 8.0
• RedHat Enterprise Linux Server Aus: 7.2, 7.3, 7.4, 7.6, 7.7, 8.2
• RedHat Enterprise Linux Server Eus: 7.6, 7.7, 8.1
• RedHat Enterprise Linux Server Tus: 7.4, 7.6, 7.7, 8.2
• RedHat Enterprise Linux Workstation: 7.0

How to fix

Upgrade to a fixed version: grub2 2.06. Check the vendor advisory for mitigations.

References

• https://bugzilla.redhat.com/show_bug.cgi?id=1900698
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZWZ36QK4IKU6MWDWNOOWKPH3WXZBHT2R/
• https://security.gentoo.org/glsa/202104-05
• https://security.netapp.com/advisory/ntap-20220325-0001/
• https://bugzilla.redhat.com/show_bug.cgi?id=1900698
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZWZ36QK4IKU6MWDWNOOWKPH3WXZBHT2R/
• https://security.gentoo.org/glsa/202104-05
• https://security.netapp.com/advisory/ntap-20220325-0001/

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