# CVE-2023-0670: File upload in Ulearn

> An administrator can achieve remote code execution on the Ulearn server by uploading malicious files disguised as images due to lack of validation.

- **Severity:** High 7.2 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 5 Apr 2023
- **Updated:** 13 Feb 2025
- **Also known as:** GHSA-vg83-7v95-762v

## What is CVE-2023-0670?

CVE-2023-0670 is a high-severity vulnerability in Ulearn, published on 5 Apr 2023. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

Ulearn version a5a7ca20de859051ea0470542844980a66dfc05d allows an attacker with administrator permissions to obtain remote code execution on the server through the image upload functionality. This occurs because the application does not validate that the uploaded image is actually an image.

Weakness: CWE-434 (Unrestricted Upload of File with Dangerous Type)

## Which versions are affected by CVE-2023-0670?

It affects 1 product.


Products: Ulearn Project Ulearn.

## How do I fix CVE-2023-0670?

No fix has been published for CVE-2023-0670 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-0670 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-0670 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-0670 and fix it if it is affected.

What it is: CVE-2023-0670 is a high-severity vulnerability in Ulearn, published on 5 Apr 2023. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-0670 exists.

Affected product: Ulearn. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2023-0670/ (Markdown: https://insights.sbomify.com/CVE-2023-0670/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-0670
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-0670
- OSV: https://osv.dev/vulnerability/CVE-2023-0670

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-0670/
Summaries are generated and may contain mistakes; the official description above is the record.