# CVE-2022-24838: Command Injection in Appointment Emails for Nextcloud Calendar

> Attackers can inject arbitrary SMTP commands via unsanitized email fields in appointment requests, potentially compromising email delivery or server integrity.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 11 Apr 2022
- **Updated:** 23 Apr 2025
- **Also known as:** GHSA-8xv5-4855-24qf

## What is CVE-2022-24838?

CVE-2022-24838 is a medium-severity command injection vulnerability in nextcloud security-advisories, published on 11 Apr 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Nextcloud Calendar is a calendar application for the nextcloud framework. SMTP Command Injection in Appointment Emails via Newlines: as newlines and special characters are not sanitized in the email value in the JSON request, a malicious attacker can inject newlines to break out of the `RCPT TO:<BOOKING USER'S EMAIL> ` SMTP command and begin injecting arbitrary SMTP commands. It is recommended that Calendar is upgraded to 3.2.2. There are no workaround available.

Weakness: CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component)

## Which versions are affected by CVE-2022-24838?

It affects 1 product.


Products: Nextcloud Calendar.

## How do I fix CVE-2022-24838?

No fix has been published for CVE-2022-24838 yet. Limit exposure of the affected software until one is available.

## Is CVE-2022-24838 being exploited?

There is no known exploitation of CVE-2022-24838 in the wild and no public exploit code.

## Other vulnerabilities in nextcloud security-advisories

- [CVE-2025-66550](https://insights.sbomify.com/CVE-2025-66550/): Nextcloud Calendar attachments of local files are offered to downloaded (medium 5.7)
- [CVE-2025-66511](https://insights.sbomify.com/CVE-2025-66511/): Nextcloud Calendar app used predictable proposal participant tokens (medium 4.8)
- [CVE-2018-3763](https://insights.sbomify.com/CVE-2018-3763/): Cross-site scripting in Nextcloud Calendar application (medium 4.8)
- [CVE-2024-37316](https://insights.sbomify.com/CVE-2024-37316/): Nextcloud Calendar's event create can create attachments that link to other websites (medium 4.6)
- [CVE-2026-45286](https://insights.sbomify.com/CVE-2026-45286/): Nextcloud: Calendar app leaked user identifiers via attendee suggestion endpoint (medium 4.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-24838 and fix it if it is affected.

What it is: CVE-2022-24838 is a medium-severity command injection vulnerability in nextcloud security-advisories, published on 11 Apr 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2022-24838 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-2022-24838/ (Markdown: https://insights.sbomify.com/CVE-2022-24838/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-24838
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-24838
- OSV: https://osv.dev/vulnerability/CVE-2022-24838

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-24838/
Summaries are generated and may contain mistakes; the official description above is the record.