# CVE-2024-43408: Discourse Placeholder Forms has a XSS stopped by CSP

> An attacker can inject malicious scripts via unsanitized user input in Discourse Placeholder Forms, potentially executing code in victim browsers.

- **Severity:** Medium 6.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 20 Aug 2024
- **Updated:** 3 Sep 2024
- **Also known as:** GHSA-9wx4-cmv3-g5jw

## What is CVE-2024-43408?

CVE-2024-43408 is a medium-severity cross-site scripting vulnerability in discourse-placeholder-theme-component, published on 20 Aug 2024. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Discourse Placeholder Forms will let you build dynamic documentation. Unsanitized and stored user input was injected in the html of the post. The vulnerability is fixed in commit a62f711d5600e4e5d86f342d52932cb6221672e7.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2024-43408?


## How do I fix CVE-2024-43408?

No fix has been published for CVE-2024-43408 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-43408 being exploited?

There is no known exploitation of CVE-2024-43408 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-43408 and fix it if it is affected.

What it is: CVE-2024-43408 is a medium-severity cross-site scripting vulnerability in discourse-placeholder-theme-component, published on 20 Aug 2024. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2024-43408 in the wild and no public exploit code.

Affected product: discourse-placeholder-theme-component. 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-2024-43408/ (Markdown: https://insights.sbomify.com/CVE-2024-43408/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-43408
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-43408
- OSV: https://osv.dev/vulnerability/CVE-2024-43408

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-43408/
Summaries are generated and may contain mistakes; the official description above is the record.