# CVE-2023-43637: Vault Key Partially Predetermined


- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 21 Sep 2023
- **Updated:** 24 Sep 2024
- **Also known as:** GHSA-g7vp-j25f-h34p, GO-2026-4436

## What is CVE-2023-43637?

CVE-2023-43637 is a high-severity vulnerability in EVE OS, published on 21 Sep 2023. 

### Official description

Due to the implementation of "deriveVaultKey", prior to version 7.10, the generated vault key
would always have the last 16 bytes predetermined to be "arfoobarfoobarfo".

This issue happens because "deriveVaultKey" calls "retrieveCloudKey" (which will always
return "foobarfoobarfoobarfoobarfoobarfo" as the key), and then merges the 32byte
randomly generated key with this key (by takeing 16bytes from each, see "mergeKeys").

This makes the key a lot weaker.

This issue does not persist in devices that were initialized on/after version 7.10, but devices
that were initialized before that and updated to a newer version still have this issue.

Roll an update that enforces the full 32bytes key usage.

Weakness: CWE-798 (Use of Hard-coded Credentials), CWE-321 (Use of Hard-coded Cryptographic Key)

## Which versions are affected by CVE-2023-43637?

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 | 0.0.0-20220310190112-c0c966dc31e2 |
| `github.com/lf-edge/eve` | Go | All versions | 0.0.0-20220310190112-c0c966dc31e2 |
| `github.com/lf-edge/eve` | Go | All versions | 0.0.0-20220310190112-c0c966dc31e2 |

Products: Lfedge Eve.

## How do I fix CVE-2023-43637?

Upgrade github.com/lf-edge/eve to 0.0.0-20220310190112-c0c966dc31e2 or later.

## Is CVE-2023-43637 being exploited?

There is no known exploitation of CVE-2023-43637 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-2023-43634](https://insights.sbomify.com/CVE-2023-43634/): Config Partition Not Protected by Measured Boot (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-43637 and fix it if it is affected.

What it is: CVE-2023-43637 is a high-severity vulnerability in EVE OS, published on 21 Sep 2023. 
Exploitation: There is no known exploitation of CVE-2023-43637 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/lf-edge/eve (Go): affected all versions; fixed in 0.0.0-20220310190112-c0c966dc31e2
- github.com/lf-edge/eve (Go): affected all versions; fixed in 0.0.0-20220310190112-c0c966dc31e2
- github.com/lf-edge/eve (Go): affected all versions; fixed in 0.0.0-20220310190112-c0c966dc31e2

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-2023-43637/ (Markdown: https://insights.sbomify.com/CVE-2023-43637/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-43637
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-43637
- OSV: https://osv.dev/vulnerability/CVE-2023-43637

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-43637/
Summaries are generated and may contain mistakes; the official description above is the record.