# CVE-2023-47122: Gitsign's Rekor public keys fetched from upstream API instead of local TUF client.

> Attackers could trick gitsign users into trusting invalid signatures by compromising the upstream Rekor API, bypassing local TUF verification.

- **Severity:** Medium 4.2 (`CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 10 Nov 2023
- **Updated:** 3 Sep 2024
- **Also known as:** GHSA-xvrc-2wvh-49vc, GO-2023-2332

## What is CVE-2023-47122?

CVE-2023-47122 is a medium-severity vulnerability in sigstore gitsign, published on 10 Nov 2023. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

### Official description

Gitsign is software for keyless Git signing using Sigstore. In versions of gitsign starting with 0.6.0 and prior to 0.8.0, Rekor public keys were fetched via the Rekor API, instead of through the local TUF client. If the upstream Rekor server happened to be compromised, gitsign clients could potentially be tricked into trusting incorrect signatures. There is no known compromise the default public good instance (`rekor.sigstore.dev`) - anyone using this instance is unaffected. This issue was fixed in v0.8.0. No known workarounds are available.

Weakness: CWE-347 (Improper Verification of Cryptographic Signature)

## Which versions are affected by CVE-2023-47122?

3 open source packages ship an affected version, including github.com/sigstore/gitsign. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/sigstore/gitsign` | Go | From 0.6.0 | 0.8.0 |
| `github.com/sigstore/gitsign` | Go | From 0.6.0 | 0.8.0 |
| `github.com/sigstore/gitsign` | Go | From 0.6.0 | 0.8.0 |

Products: Sigstore Gitsign.

## How do I fix CVE-2023-47122?

Upgrade github.com/sigstore/gitsign to 0.8.0 or later.

## Is CVE-2023-47122 being exploited?

There is no known exploitation of CVE-2023-47122 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-47122 and fix it if it is affected.

What it is: CVE-2023-47122 is a medium-severity vulnerability in sigstore gitsign, published on 10 Nov 2023. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2023-47122 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/sigstore/gitsign (Go): affected from 0.6.0; fixed in 0.8.0
- github.com/sigstore/gitsign (Go): affected from 0.6.0; fixed in 0.8.0
- github.com/sigstore/gitsign (Go): affected from 0.6.0; fixed in 0.8.0

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-2023-47122/ (Markdown: https://insights.sbomify.com/CVE-2023-47122/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-47122
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-47122
- OSV: https://osv.dev/vulnerability/CVE-2023-47122

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-47122/
Summaries are generated and may contain mistakes; the official description above is the record.