CVE-2025-0690 Grub2: read: integer overflow may lead to out-of-bounds write

Description

The read command is used to read the keyboard input from the user, while reads it keeps the input length in a 32-bit integer value which is further used to reallocate the line buffer to accept the next character. During this process, with a line big enough it's possible to make this variable to overflow leading to a out-of-bounds write in the heap based buffer. This flaw may be leveraged to corrupt grub's internal critical data and secure boot bypass is not discarded as consequence.

Exploitable with physical access to the machine, with an administrator account and if a user takes an action; an attacker can seriously compromise confidentiality, integrity or availability.

Attack vector

Physical

Attack complexity

Low

Privileges required

High

Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Affected products and versions