# CVE-2021-22877: Information disclosure in Nextcloud Server

> Missing user check in Nextcloud Server allows attackers to view other users' external storage credentials if not previously configured.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 3 Mar 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-v65r-wc6r-r9x8

## What is CVE-2021-22877?

CVE-2021-22877 is a medium-severity vulnerability in Fedoraproject Fedora, published on 3 Mar 2021. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

A missing user check in Nextcloud prior to 20.0.6 inadvertently populates a user's own credentials for other users external storage configuration when not already configured yet.

Weakness: CWE-862 (Missing Authorization), CWE-284 (Improper Access Control)

## Which versions are affected by CVE-2021-22877?

It affects 2 products.


Products: Fedoraproject Fedora, Nextcloud Nextcloud Server.

## How do I fix CVE-2021-22877?

No fix has been published for CVE-2021-22877 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-22877 being exploited?

There is no known exploitation of CVE-2021-22877 in the wild and no public exploit code.

## Other vulnerabilities in Fedoraproject Fedora

- [CVE-2024-4577](https://insights.sbomify.com/CVE-2024-4577/): PHP-CGI OS Command Injection (critical 9.8, exploited in the wild)
- [CVE-2021-39226](https://insights.sbomify.com/CVE-2021-39226/): Grafana Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2019-5544](https://insights.sbomify.com/CVE-2019-5544/): VMware ESXi and Horizon DaaS OpenSLP Heap-Based Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2024-4947](https://insights.sbomify.com/CVE-2024-4947/): Google Chromium V8 Type Confusion (critical 9.6, exploited in the wild)
- [CVE-2024-4671](https://insights.sbomify.com/CVE-2024-4671/): Google Chromium Visuals Use-After-Free (critical 9.6, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-22877 and fix it if it is affected.

What it is: CVE-2021-22877 is a medium-severity vulnerability in Fedoraproject Fedora, published on 3 Mar 2021. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-22877 in the wild and no public exploit code.

Affected product: Fedoraproject Fedora. 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-2021-22877/ (Markdown: https://insights.sbomify.com/CVE-2021-22877/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-22877
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-22877
- OSV: https://osv.dev/vulnerability/CVE-2021-22877

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-22877/
Summaries are generated and may contain mistakes; the official description above is the record.