# CVE-2023-45131: Unauthenticated access to new private chat messages in Discourse

> Unauthenticated attackers can read new private chat messages in Discourse by sending a POST request to MessageBus, exposing sensitive user communications.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 16 Oct 2023
- **Updated:** 16 Sep 2024
- **Also known as:** BIT-discourse-2023-45131, GHSA-84gf-hhrc-9pw6

## What is CVE-2023-45131?

CVE-2023-45131 is a high-severity missing authorization vulnerability in Discourse Discourse, published on 16 Oct 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Discourse is an open source platform for community discussion. New chat messages can be read by making an unauthenticated POST request to MessageBus. This issue is patched in the 3.1.1 stable and 3.2.0.beta2 versions of Discourse. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Weakness: CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2023-45131?

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


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `discourse` | Bitnami | All versions to 3.1.1 | None |

Products: Discourse Discourse.

## How do I fix CVE-2023-45131?

No fix has been published for CVE-2023-45131 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-45131 being exploited?

There is no known exploitation of CVE-2023-45131 in the wild and no public exploit code.

Public exploit code:

- Discourse 3.1.1 - Unauthenticated Chat Message Access (exploitdb)

## 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-2023-45131 and fix it if it is affected.

What it is: CVE-2023-45131 is a high-severity missing authorization vulnerability in Discourse Discourse, published on 16 Oct 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-45131 in the wild and no public exploit code.

Affected packages and fixed versions:
- discourse (Bitnami): affected all versions up to 3.1.1; 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/CVE-2023-45131/ (Markdown: https://insights.sbomify.com/CVE-2023-45131/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-45131
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-45131
- OSV: https://osv.dev/vulnerability/CVE-2023-45131

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-45131/
Summaries are generated and may contain mistakes; the official description above is the record.