# CVE-2023-6721: Improper Restriction of XML External Entity Reference in Repox

> A remote attacker can exploit an XML External Entity vulnerability in Repox to access the server's file system and disrupt operations.

- **Severity:** High 8.3 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L`)
- **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:** 13 Dec 2023
- **Updated:** 2 Aug 2024
- **Also known as:** GHSA-gfqh-8v9q-f2vf

## What is CVE-2023-6721?

CVE-2023-6721 is a high-severity vulnerability in Repox, published on 13 Dec 2023. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

An XEE vulnerability has been found in Repox, which allows a remote attacker to interfere with the application's XML data processing in the fileupload function, resulting in interaction between the attacker and the server's file system.

Weakness: CWE-611 (Improper Restriction of XML External Entity Reference)

## Which versions are affected by CVE-2023-6721?

It affects 1 product.


Products: Europeana Repox.

## How do I fix CVE-2023-6721?

No fix has been published for CVE-2023-6721 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-6721 being exploited?

There is no known exploitation of CVE-2023-6721 in the wild and no public exploit code.

## Other vulnerabilities in Repox

- [CVE-2023-6723](https://insights.sbomify.com/CVE-2023-6723/): Unrestricted Upload of File with Dangerous Type in Repox (critical 10.0)
- [CVE-2023-6718](https://insights.sbomify.com/CVE-2023-6718/): Authentication Bypass Using an Alternate Path or Channel in Repox (critical 9.4)
- [CVE-2023-6722](https://insights.sbomify.com/CVE-2023-6722/): Relative Path Traversal in Repox (high 7.5)
- [CVE-2023-6719](https://insights.sbomify.com/CVE-2023-6719/): Cross-site Scripting in Repox (medium 6.3)
- [CVE-2023-6720](https://insights.sbomify.com/CVE-2023-6720/): Cross-site Scripting in Repox (medium 5.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-6721 and fix it if it is affected.

What it is: CVE-2023-6721 is a high-severity vulnerability in Repox, published on 13 Dec 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-2023-6721 in the wild and no public exploit code.

Affected product: Repox. 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-2023-6721/ (Markdown: https://insights.sbomify.com/CVE-2023-6721/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-6721
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-6721
- OSV: https://osv.dev/vulnerability/CVE-2023-6721

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-6721/
Summaries are generated and may contain mistakes; the official description above is the record.