CVE-2023-39950
Siemens · published 2023-08-14
Source record Collected from the National Vulnerability Database (NVD)
Description
Description by GitHub, Inc. via the CVE Program.
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.
Filed by GitHub, Inc.; not a statement by Siemens.
Status at the source
- NVD status: Modified
Affected products, as the source lists them
| Vendor | Product | Versions |
|---|---|---|
| siemens | efibootguard | < 0.15: affected |
Products named in NVD's CPE match criteria (1)
cpe:2.3:a:siemens:efibootguard:*:*:*:*:*:*:*:*
DeSpy has not checked any unit, hardware revision or firmware. A product missing here is not a statement that it is unaffected.
Scores, as their sources published them
- CVSS 3.1: 6.1 MEDIUM — as published by GitHub, Inc. (Secondary)
CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:L - CVSS 3.1: 5.2 MEDIUM — as published by NIST (Primary)
CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L - SSVC — CISA's assessment (SSVC 2.0.3, CISA Coordinator): Exploitation: none · Automatable: no · Technical impact: partial
DeSpy does not score records. These are the sources' own values.
Weaknesses
Sources
References the source lists
- https://github.com/siemens/efibootguard/blob/master/docs/API.md
- https://github.com/siemens/efibootguard/blob/master/docs/TOOLS.md
- https://github.com/siemens/efibootguard/blob/master/docs/TOOLS.md#setting-user-variables
- https://github.com/siemens/efibootguard/security/advisories/GHSA-j6pp-7g99-24m7
- https://github.com/siemens/efibootguard/tags
- https://github.com/siemens/efibootguard/blob/master/docs/API.md
- https://github.com/siemens/efibootguard/blob/master/docs/TOOLS.md
- https://github.com/siemens/efibootguard/blob/master/docs/TOOLS.md#setting-user-variables
- https://github.com/siemens/efibootguard/security/advisories/GHSA-j6pp-7g99-24m7
- https://github.com/siemens/efibootguard/tags
Source dates: published 2023-08-14, last changed 2026-06-17. DeSpy's copy of this version is dated 2026-09-28.
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