# CVE-2023-37467: Discourse CSP nonce reuse vulnerability for anonymous users

> CSP nonce reuse allows XSS attacks to bypass Content Security Policy protections for anonymous users in Discourse.

- **Severity:** Medium 6.8 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N`)
- **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:** 28 Jul 2023
- **Updated:** 10 Oct 2024
- **Also known as:** BIT-discourse-2023-37467, GHSA-gr5h-hm62-jr3j

## What is CVE-2023-37467?

CVE-2023-37467 is a medium-severity cross-site scripting vulnerability in Discourse Discourse, published on 28 Jul 2023. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Discourse is an open source discussion platform. Prior to version 3.1.0.beta7 of the `beta` and `tests-passed` branches, a CSP (Content Security Policy) nonce reuse vulnerability was discovered could allow cross-site scripting (XSS) attacks to bypass CSP protection for anonymous (i.e. unauthenticated) users. There are no known XSS vectors at the moment, but should one be discovered, this vulnerability would allow the XSS attack to bypass CSP and execute successfully. This vulnerability isn't applicable to logged-in users. Version 3.1.0.beta7 contains a patch. The stable branch doesn't have this vulnerability. A workaround to prevent the vulnerability is to disable Google Tag Manager, i.e., unset the `gtm container id` setting.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation), CWE-323 (Reusing a Nonce, Key Pair in Encryption)

## Which versions are affected by CVE-2023-37467?

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


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `discourse` | Bitnami | From 1.1.0-beta1 to 1.1.0-beta1 | None |

Products: Discourse Discourse.

## How do I fix CVE-2023-37467?

No fix has been published for CVE-2023-37467 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-37467 being exploited?

There is no known exploitation of CVE-2023-37467 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-2023-37467 and fix it if it is affected.

What it is: CVE-2023-37467 is a medium-severity cross-site scripting vulnerability in Discourse Discourse, published on 28 Jul 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-2023-37467 in the wild and no public exploit code.

Affected packages and fixed versions:
- discourse (Bitnami): affected from 1.1.0-beta1 up to 1.1.0-beta1; 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-2023-37467/ (Markdown: https://insights.sbomify.com/CVE-2023-37467/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-37467
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-37467
- OSV: https://osv.dev/vulnerability/CVE-2023-37467

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-37467/
Summaries are generated and may contain mistakes; the official description above is the record.