# CVE-2021-22896: Missing authorization in Nextcloud Mail

> Authenticated users can create mail aliases for other users due to missing permission checks in Nextcloud Mail.

- **Severity:** Medium 4.3 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N`)
- **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:** 11 Jun 2021
- **Updated:** 3 Aug 2024
- **Also known as:** BIT-nextcloud-2021-22896, GHSA-jmgp-77jq-fjp3

## What is CVE-2021-22896?

CVE-2021-22896 is a medium-severity missing authorization vulnerability in Nextcloud Mail, published on 11 Jun 2021. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Nextcloud Mail before 1.9.5 suffers from improper access control due to a missing permission check allowing other authenticated users to create mail aliases for other users.

Weakness: CWE-862 (Missing Authorization)

## Which versions are affected by CVE-2021-22896?

1 open source package ship an affected version, including nextcloud. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `nextcloud` | Bitnami | All versions | 1.9.5 |

Products: Nextcloud Nextcloud.

## How do I fix CVE-2021-22896?

Upgrade nextcloud to 1.9.5 or later.

## Is CVE-2021-22896 being exploited?

There is no known exploitation of CVE-2021-22896 in the wild and no public exploit code.

## Other vulnerabilities in Nextcloud Mail

- [CVE-2019-5454](https://insights.sbomify.com/CVE-2019-5454/): SQL injection in com.nextcloud.client (critical 9.8)
- [CVE-2021-43863](https://insights.sbomify.com/CVE-2021-43863/): SQL Injection in FileContentProvider (GHSL-2021-1007) (high 7.5)
- [CVE-2019-5450](https://insights.sbomify.com/CVE-2019-5450/): Cross-site scripting in com.nextcloud.client (medium 6.8)
- [CVE-2019-5455](https://insights.sbomify.com/CVE-2019-5455/): Auth bypass in com.nextcloud.client (medium 6.8)
- [CVE-2021-22905](https://insights.sbomify.com/CVE-2021-22905/): Information disclosure in Nextcloud Android App (com.nextcloud.client) (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-22896 and fix it if it is affected.

What it is: CVE-2021-22896 is a medium-severity missing authorization vulnerability in Nextcloud Mail, published on 11 Jun 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-22896 in the wild and no public exploit code.

Affected packages and fixed versions:
- nextcloud (Bitnami): affected all versions; fixed in 1.9.5

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-2021-22896/ (Markdown: https://insights.sbomify.com/CVE-2021-22896/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-22896
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-22896
- OSV: https://osv.dev/vulnerability/CVE-2021-22896

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-22896/
Summaries are generated and may contain mistakes; the official description above is the record.