# CVE-2021-39223: File path disclosure of shared files in Richdocuments application

> An attacker can view full file paths of shared documents due to verbose error messages in the Nextcloud Richdocuments application.

- **Severity:** Medium 4.8 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:N/A:N`)
- **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:** No
- **Published:** 25 Oct 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-rjcc-4cgj-6v93

## What is CVE-2021-39223?

CVE-2021-39223 is a medium-severity vulnerability in nextcloud security-advisories, published on 25 Oct 2021. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

Nextcloud is an open-source, self-hosted productivity platform. The Nextcloud Richdocuments application prior to versions 3.8.6 and 4.2.3 returned verbatim exception messages to the user. This could result in a full path disclosure on shared files. (e.g. an attacker could see that the file `shared.txt` is located within `/files/$username/Myfolder/Mysubfolder/shared.txt`). It is recommended that the Richdocuments application is upgraded to 3.8.6 or 4.2.3. As a workaround, disable the Richdocuments application in the app settings.

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

## Which versions are affected by CVE-2021-39223?

It affects 1 product.


Products: Nextcloud Richdocuments.

## How do I fix CVE-2021-39223?

No fix has been published for CVE-2021-39223 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-39223 being exploited?

There is no known exploitation of CVE-2021-39223 in the wild and no public exploit code.

## Other vulnerabilities in nextcloud security-advisories

- [CVE-2021-37628](https://insights.sbomify.com/CVE-2021-37628/): File Drop can be bypassed using Richdocuments app in nextcloud (high 7.5)
- [CVE-2022-31024](https://insights.sbomify.com/CVE-2022-31024/): Federated editing allows iframing remote servers by default in richdocuments (medium 6.5)
- [CVE-2023-25150](https://insights.sbomify.com/CVE-2023-25150/): Document content of files can be obtained through Collabora for files of other users (medium 5.8)
- [CVE-2023-28645](https://insights.sbomify.com/CVE-2023-28645/): Secure view can be bypassed by using internal API endpoint in Nextcloud richdocuments (medium 5.7)
- [CVE-2021-37629](https://insights.sbomify.com/CVE-2021-37629/): Lack of ratelimit on Richdocuments OCS endpoint in nextcloud (medium 5.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-39223 and fix it if it is affected.

What it is: CVE-2021-39223 is a medium-severity vulnerability in nextcloud security-advisories, published on 25 Oct 2021. 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 CVE-2021-39223 in the wild and no public exploit code.

Affected product: nextcloud security-advisories. 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-2021-39223/ (Markdown: https://insights.sbomify.com/CVE-2021-39223/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-39223
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-39223
- OSV: https://osv.dev/vulnerability/CVE-2021-39223

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-39223/
Summaries are generated and may contain mistakes; the official description above is the record.