# GHSA-r2h5-3hgw-8j34: User data in TPM attestation vulnerable to MITM

> A privileged insider can bypass TPM attestation checks to join a malicious node to a Constellation cluster, compromising cluster integrity.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Feb 2023
- **Also known as:** GO-2023-1583

## What is GHSA-r2h5-3hgw-8j34?

GHSA-r2h5-3hgw-8j34 is a vulnerability in github.com/edgelesssys/constellation, published on 17 Feb 2023. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

### Impact
Attestation *user data* (such as the digest of the public key in an aTLS connection) was bound to the issuer's TPM, but not to its PCR state. An attacker could intercept a node initialization, initialize the node themselves, and then impersonate an uninitialized node to the validator. In practice, this meant that a CSP insider with sufficient privileges would have been able to join a node under their control to a Constellation cluster.

### Patches
The issue has been patched in [v2.5.2](https://github.com/edgelesssys/constellation/releases/tag/v2.5.2).

### Workarounds
none

## Which versions are affected by GHSA-r2h5-3hgw-8j34?

4 open source packages ship an affected version, including github.com/edgelesssys/constellation/v2 and github.com/edgelesssys/constellation.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/edgelesssys/constellation/v2` | Go | All versions | 2.5.2 |
| `github.com/edgelesssys/constellation/v2` | Go | All versions | 2.5.2 |
| `github.com/edgelesssys/constellation/v2` | Go | All versions | 2.5.2 |
| `github.com/edgelesssys/constellation` | Go | All versions | None |

## How do I fix GHSA-r2h5-3hgw-8j34?

Upgrade github.com/edgelesssys/constellation/v2 to 2.5.2 or later.

## Is GHSA-r2h5-3hgw-8j34 being exploited?

There is no known exploitation of GHSA-r2h5-3hgw-8j34 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for GHSA-r2h5-3hgw-8j34 and fix it if it is affected.

What it is: GHSA-r2h5-3hgw-8j34 is a vulnerability in github.com/edgelesssys/constellation, published on 17 Feb 2023. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of GHSA-r2h5-3hgw-8j34 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/edgelesssys/constellation/v2 (Go): affected all versions; fixed in 2.5.2
- github.com/edgelesssys/constellation/v2 (Go): affected all versions; fixed in 2.5.2
- github.com/edgelesssys/constellation/v2 (Go): affected all versions; fixed in 2.5.2
- github.com/edgelesssys/constellation (Go): affected all versions; no fix listed

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/GHSA-r2h5-3hgw-8j34/ (Markdown: https://insights.sbomify.com/GHSA-r2h5-3hgw-8j34/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/GHSA-r2h5-3hgw-8j34

---
From sbomify Insights: https://insights.sbomify.com/GHSA-r2h5-3hgw-8j34/
Summaries are generated and may contain mistakes; the official description above is the record.