# CVE-2023-37904: Discourse Race Condition in Accept Invite

> Attackers can bypass invite limits to create unauthorized accounts in Discourse forums, requiring an upgrade to patched versions.

- **Severity:** Low 2.6 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 28 Jul 2023
- **Updated:** 10 Oct 2024
- **Also known as:** BIT-discourse-2023-37904, GHSA-6wj5-4ph2-c7qg

## What is CVE-2023-37904?

CVE-2023-37904 is a low-severity vulnerability in Discourse Discourse, published on 28 Jul 2023. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

Discourse is an open source discussion platform. Prior to version 3.0.6 of the `stable` branch and version 3.1.0.beta7 of the `beta` and `tests-passed` branches, more users than permitted could be created from invite links. The issue is patched in version 3.0.6 of the `stable` branch and version 3.1.0.beta7 of the `beta` and `tests-passed` branches. As a workaround, use restrict to email address invites.

Weakness: CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization)

## Which versions are affected by CVE-2023-37904?

1 open source package ship an affected version, including discourse. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `discourse` | Bitnami | All versions | 3.0.6 |

Products: Discourse Discourse.

## How do I fix CVE-2023-37904?

Upgrade discourse to 3.0.6 or later.

## Is CVE-2023-37904 being exploited?

There is no known exploitation of CVE-2023-37904 in the wild and no public exploit code.

## Other vulnerabilities in Discourse Discourse

- [CVE-2021-41163](https://insights.sbomify.com/CVE-2021-41163/): RCE via malicious SNS subscription payload (critical 10.0)
- [CVE-2022-36066](https://insights.sbomify.com/CVE-2022-36066/): Discourse vulnerable to RCE via admins uploading maliciously zipped file (critical 9.1)
- [CVE-2022-39356](https://insights.sbomify.com/CVE-2022-39356/): Discourse user account takeover via email and invite link (high 8.9)
- [CVE-2023-22468](https://insights.sbomify.com/CVE-2023-22468/): Discourse vulnerable to Cross-site Scripting in local oneboxes (high 8.8)
- [CVE-2026-27934](https://insights.sbomify.com/CVE-2026-27934/): Discourse leaks private topic title and post excerpt via user action API endpoint (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-37904 and fix it if it is affected.

What it is: CVE-2023-37904 is a low-severity vulnerability in Discourse Discourse, published on 28 Jul 2023. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2023-37904 in the wild and no public exploit code.

Affected packages and fixed versions:
- discourse (Bitnami): affected all versions; fixed in 3.0.6

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-2023-37904/ (Markdown: https://insights.sbomify.com/CVE-2023-37904/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-37904
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-37904
- OSV: https://osv.dev/vulnerability/CVE-2023-37904

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-37904/
Summaries are generated and may contain mistakes; the official description above is the record.