# CVE-2020-8154: Missing authorization in Nextcloud Server

> An attacker can remotely wipe other users' devices by sending a malicious request to an unprotected endpoint in Nextcloud Server.

- **Severity:** High 7.7 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 12 May 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-r63f-25g5-v4wf

## What is CVE-2020-8154?

CVE-2020-8154 is a high-severity missing authorization vulnerability in Nextcloud Nextcloud Server, published on 12 May 2020. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

An Insecure direct object reference vulnerability in Nextcloud Server 18.0.2 allowed an attacker to remote wipe devices of other users when sending a malicious request directly to the endpoint.

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

## Which versions are affected by CVE-2020-8154?

It affects 1 product.


Products: Nextcloud Nextcloud Server.

## How do I fix CVE-2020-8154?

Upgrade to a fixed version.

## Is CVE-2020-8154 being exploited?

There is no known exploitation of CVE-2020-8154 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-2020-8154 and fix it if it is affected.

What it is: CVE-2020-8154 is a high-severity missing authorization vulnerability in Nextcloud Nextcloud Server, published on 12 May 2020. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-8154 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-2020-8154/ (Markdown: https://insights.sbomify.com/CVE-2020-8154/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-8154
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-8154
- OSV: https://osv.dev/vulnerability/CVE-2020-8154

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-8154/
Summaries are generated and may contain mistakes; the official description above is the record.