CVE-2020-27749 Information

Description

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.

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

Reference

https://bugzilla.redhat.com/show_bug.cgi?id=1899966 https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ZWZ36QK4IKU6MWDWNOOWKPH3WXZBHT2R/ https://security.gentoo.org/glsa/202104-05 https://security.netapp.com/advisory/ntap-20220325-0001/

Attack Complexity

LOW

Privileges Required

HIGH

User Interaction Required

HIGH

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

HIGH

Availability Impact

HIGH

Base Score

HIGH

Base Severity

6.7