# CVE-2017-0936: Missing authorization in Nextcloud Server

> Logged-in users can modify app password scopes of other users due to missing ownership checks in Nextcloud Server.

- **Severity:** Medium 5.7 (`CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:H/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:** 28 Mar 2018
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-84fw-wvq7-7x27

## What is CVE-2017-0936?

CVE-2017-0936 is a medium-severity missing authorization vulnerability in Nextcloud Nextcloud Server, published on 28 Mar 2018. 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 Server before 11.0.7 and 12.0.5 suffers from an Authorization Bypass Through User-Controlled Key vulnerability. A missing ownership check allowed logged-in users to change the scope of app passwords of other users. Note that the app passwords themselves where neither disclosed nor could the error be misused to identify as another user.

Weakness: CWE-639 (Authorization Bypass Through User-Controlled Key)

## Which versions are affected by CVE-2017-0936?

It affects 1 product.


Products: Nextcloud Nextcloud Server.

## How do I fix CVE-2017-0936?

No fix has been published for CVE-2017-0936 yet. Limit exposure of the affected software until one is available.

## Is CVE-2017-0936 being exploited?

There is no known exploitation of CVE-2017-0936 in the wild and no public exploit code.

## Other vulnerabilities in Nextcloud Nextcloud Server

- [CVE-2021-32802](https://insights.sbomify.com/CVE-2021-32802/): Preview generation used third-party library not suited for user-generated content in Nextcloud server (critical 9.3)
- [CVE-2023-26482](https://insights.sbomify.com/CVE-2023-26482/): Scope of workflow operations is not validated in nextcloud server (critical 9.1)
- [CVE-2018-3775](https://insights.sbomify.com/CVE-2018-3775/): Auth bypass in Nextcloud Server (high 8.8)
- [CVE-2023-35172](https://insights.sbomify.com/CVE-2023-35172/): Nextcloud Server password reset endpoint is not brute force protected (high 8.7)
- [CVE-2023-32320](https://insights.sbomify.com/CVE-2023-32320/): Nextcloud Server's brute force protection allows someone to send more requests than intended (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2017-0936 and fix it if it is affected.

What it is: CVE-2017-0936 is a medium-severity missing authorization vulnerability in Nextcloud Nextcloud Server, published on 28 Mar 2018. 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-2017-0936 in the wild and no public exploit code.

Affected product: Nextcloud Nextcloud Server. 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-2017-0936/ (Markdown: https://insights.sbomify.com/CVE-2017-0936/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-0936
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-0936
- OSV: https://osv.dev/vulnerability/CVE-2017-0936

---
From sbomify Insights: https://insights.sbomify.com/CVE-2017-0936/
Summaries are generated and may contain mistakes; the official description above is the record.