# CVE-2023-43634: Config Partition Not Protected by Measured Boot

> Attackers can modify the configuration partition without detection, gaining full device control and access to encrypted vault keys due to a measured boot bypass.

- **Severity:** High 8.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 21 Sep 2023
- **Updated:** 24 Sep 2024
- **Also known as:** GHSA-wc42-fcjp-v8vq, GO-2026-4432

## What is CVE-2023-43634?

CVE-2023-43634 is a high-severity vulnerability in EVE OS, published on 21 Sep 2023. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

When sealing/unsealing the “vault” key, a list of PCRs is used, which defines which PCRs
are used.

In a previous project, CYMOTIVE found that the configuration is not protected by the secure
boot, and in response Zededa implemented measurements on the config partition that was
mapped to PCR 13.

In that process, PCR 13 was added to the list of PCRs that seal/unseal the key.

In commit “56e589749c6ff58ded862d39535d43253b249acf”, the config partition
measurement moved from PCR 13 to PCR 14, but PCR 14 was not added to the list of
PCRs that seal/unseal the key.

This change makes the measurement of PCR 14 effectively redundant as it would not affect
the sealing/unsealing of the key.

An attacker could modify the config partition without triggering the measured boot, this could
result in the attacker gaining full control over the device with full access to the contents of the
encrypted “vault”

Weakness: CWE-922 (Insecure Storage of Sensitive Information), CWE-522 (Insufficiently Protected Credentials)

## Which versions are affected by CVE-2023-43634?

3 open source packages ship an affected version, including github.com/lf-edge/eve. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/lf-edge/eve` | Go | All versions | 0.0.0-20230519072751-977f42b07fa9 |
| `github.com/lf-edge/eve` | Go | All versions | 0.0.0-20230519072751-977f42b07fa9 |
| `github.com/lf-edge/eve` | Go | All versions | 0.0.0-20230519072751-977f42b07fa9 |

Products: Lfedge Eve.

## How do I fix CVE-2023-43634?

Upgrade github.com/lf-edge/eve to 0.0.0-20230519072751-977f42b07fa9 or later.

## Is CVE-2023-43634 being exploited?

There is no known exploitation of CVE-2023-43634 in the wild and no public exploit code.

## Other vulnerabilities in EVE OS

- [CVE-2023-43633](https://insights.sbomify.com/CVE-2023-43633/): Debug Functions Unlockable Without Triggering Measured Boot (high 8.8)
- [CVE-2023-43637](https://insights.sbomify.com/CVE-2023-43637/): Vault Key Partially Predetermined (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-43634 and fix it if it is affected.

What it is: CVE-2023-43634 is a high-severity vulnerability in EVE OS, published on 21 Sep 2023. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-43634 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/lf-edge/eve (Go): affected all versions; fixed in 0.0.0-20230519072751-977f42b07fa9
- github.com/lf-edge/eve (Go): affected all versions; fixed in 0.0.0-20230519072751-977f42b07fa9
- github.com/lf-edge/eve (Go): affected all versions; fixed in 0.0.0-20230519072751-977f42b07fa9

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2023-43634/ (Markdown: https://insights.sbomify.com/CVE-2023-43634/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-43634
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-43634
- OSV: https://osv.dev/vulnerability/CVE-2023-43634

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-43634/
Summaries are generated and may contain mistakes; the official description above is the record.