# CVE-2023-40020: Improper Authentication in PrivateUploader

> Attackers can bypass admin checks to modify data because the application continues processing requests despite returning a 403 error.

- **Severity:** Critical 9.9 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 14 Aug 2023
- **Updated:** 1 Oct 2024
- **Also known as:** GHSA-vhrw-2472-rrjx

## What is CVE-2023-40020?

CVE-2023-40020 is a critical authentication bypass vulnerability in PrivateUploader, published on 14 Aug 2023. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

PrivateUploader is an open source image hosting server written in Vue and TypeScript. In affected versions `app/routes/v3/admin.controller.ts` did not correctly verify whether the user was an administrator (High Level) or moderator (Low Level) causing the request to continue processing. The response would be a 403 with ADMIN_ONLY, however, next() would call leading to any updates/changes in the route to process. This issue has been addressed in version 3.2.49. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Weakness: CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2023-40020?

It affects 1 product.


Products: Troplo Privateuploader.

## How do I fix CVE-2023-40020?

No fix has been published for CVE-2023-40020 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-40020 being exploited?

There is no known exploitation of CVE-2023-40020 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-40020 and fix it if it is affected.

What it is: CVE-2023-40020 is a critical authentication bypass vulnerability in PrivateUploader, published on 14 Aug 2023. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-40020 in the wild and no public exploit code.

Affected product: PrivateUploader. 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-2023-40020/ (Markdown: https://insights.sbomify.com/CVE-2023-40020/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-40020
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-40020
- OSV: https://osv.dev/vulnerability/CVE-2023-40020

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-40020/
Summaries are generated and may contain mistakes; the official description above is the record.