CVE-2023-39950

Publication date 14 August 2023

Last updated 11 July 2025

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

6.1 · Medium

Score breakdown

Description

efibootguard is a simple UEFI boot loader with support for safely switching between current and updated partition sets. Insufficient or missing validation and sanitization of input from untrustworthy bootloader environment files can cause crashes and probably also code injections into `bg_setenv`) or programs using `libebgenv`. This is triggered when the affected components try to modify a manipulated environment, in particular its user variables. Furthermore, `bg_printenv` may crash over invalid read accesses or report invalid results. Not affected by this issue is EFI Boot Guard's bootloader EFI binary. EFI Boot Guard release v0.15 contains required patches to sanitize and validate the bootloader environment prior to processing it in userspace. Its library and tools should be updated, so should programs statically linked against it. An update of the bootloader EFI executable is not required. The only way to prevent the issue with an unpatched EFI Boot Guard version is to avoid accesses to user variables, specifically modifications to them.

Status

Package Ubuntu Release Status
efibootguard 26.04 LTS resolute
Needs evaluation
25.10 questing Ignored end of life, was needs-triage
25.04 plucky Ignored end of life, was needs-triage
24.10 oracular Ignored end of life, was needs-triage
24.04 LTS noble
Needs evaluation
23.10 mantic Ignored end of life, was needs-triage
23.04 lunar Ignored end of life, was needs-triage
22.04 LTS jammy Not in release
20.04 LTS focal Not in release
18.04 LTS bionic Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release

Severity score breakdown

CVSS version: CVSS v3.0

Base score 6.1 · Medium

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

References

Other references

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