CVE-2020-27749: Fedoraproject Fedora

Medium severity, CVSS 6.7. EPSS: 0.6% chance of exploitation in the next 30 days.

A flaw was found in grub2 in versions prior to 2.06. Variable names present are expanded in the supplied command line into their corresponding variable contents, using a 1kB stack buffer for temporary storage, without sufficient bounds checking. If the function is called with a command line that references a variable with a sufficiently large payload, it is possible to overflow the stack buffer, corrupt the stack frame and control execution which could also circumvent Secure Boot protections. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

Affected products

• Fedoraproject Fedora: version 33 only; version 34 only
• GNU GRUB2: before 2.06 (fixed in 2.06)
• Netapp Ontap Select Deploy Administration Utility: affected versions not specified
• Red Hat Enterprise Linux: version 7.0 only; version 8.0 only
• Red Hat Enterprise Linux Server Aus: version 7.2 only; version 7.3 only; version 7.4 only; version 7.6 only; version 7.7 only; version 8.2 only
• Red Hat Enterprise Linux Server Eus: version 7.6 only; version 7.7 only; version 8.1 only
• Red Hat Enterprise Linux Server Tus: version 7.4 only; version 7.6 only; version 7.7 only; version 8.2 only
• Red Hat Enterprise Linux Workstation: version 7.0 only

Published 2021-03-03. Last modified 2026-06-17.