# GHSA-wg8h-gxf4-g4gh: TYPO3 Cross-Site Scripting in Online Media Asset Rendering

> An authenticated backend user can inject malicious scripts via online media assets, leading to cross-site scripting attacks against other users.

- **Severity:** Not scored
- **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:** 30 May 2024

## What is GHSA-wg8h-gxf4-g4gh?

GHSA-wg8h-gxf4-g4gh is a cross-site scripting vulnerability in typo3/cms-core, published on 30 May 2024. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

Failing to properly encode user input, online media asset rendering (*.youtube and *.vimeo files) is vulnerable to cross-site scripting. A valid backend user account or write access on the server system (e.g. SFTP) is needed in order to exploit this vulnerability.

## Which versions are affected by GHSA-wg8h-gxf4-g4gh?

4 open source packages ship an affected version, including typo3/cms-core.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `typo3/cms-core` | Packagist | From 8.0.0 | 8.7.21 |
| `typo3/cms-core` | Packagist | From 8.0.0 | 8.7.21 |
| `typo3/cms-core` | Packagist | From 9.0.0 | 9.5.2 |
| `typo3/cms-core` | Packagist | From 9.0.0 | 9.5.2 |

## How do I fix GHSA-wg8h-gxf4-g4gh?

Upgrade typo3/cms-core to a fixed version for your release line: 8.7.21 or 9.5.2.

## Is GHSA-wg8h-gxf4-g4gh being exploited?

There is no known exploitation of GHSA-wg8h-gxf4-g4gh in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for GHSA-wg8h-gxf4-g4gh and fix it if it is affected.

What it is: GHSA-wg8h-gxf4-g4gh is a cross-site scripting vulnerability in typo3/cms-core, published on 30 May 2024. 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 GHSA-wg8h-gxf4-g4gh in the wild and no public exploit code.

Affected packages and fixed versions:
- typo3/cms-core (Packagist): affected from 8.0.0; fixed in 8.7.21
- typo3/cms-core (Packagist): affected from 8.0.0; fixed in 8.7.21
- typo3/cms-core (Packagist): affected from 9.0.0; fixed in 9.5.2
- typo3/cms-core (Packagist): affected from 9.0.0; fixed in 9.5.2

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/GHSA-wg8h-gxf4-g4gh/ (Markdown: https://insights.sbomify.com/GHSA-wg8h-gxf4-g4gh/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/GHSA-wg8h-gxf4-g4gh

---
From sbomify Insights: https://insights.sbomify.com/GHSA-wg8h-gxf4-g4gh/
Summaries are generated and may contain mistakes; the official description above is the record.