# CVE-2023-33183: Error in calendar when booking an appointment reveals the full path of the website

> An attacker can obtain internal website paths when the SMTP server is unavailable, potentially aiding further attacks.

- **Severity:** Low 2.6 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:N/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:** 30 May 2023
- **Updated:** 10 Jan 2025
- **Also known as:** GHSA-2792-2734-hr7j

## What is CVE-2023-33183?

CVE-2023-33183 is a low-severity vulnerability in nextcloud security-advisories, published on 30 May 2023. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

Calendar app for Nextcloud easily sync events from various devices with your Nextcloud. Some internal paths of the website are disclosed when the SMTP server is unavailable. It is recommended that the Calendar app is updated to 3.5.5 or 4.2.3

Weakness: CWE-285 (Improper Authorization)

## Which versions are affected by CVE-2023-33183?

It affects 1 product.


Products: Nextcloud Calendar.

## How do I fix CVE-2023-33183?

No fix has been published for CVE-2023-33183 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-33183 being exploited?

There is no known exploitation of CVE-2023-33183 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-2022-24838](https://insights.sbomify.com/CVE-2022-24838/): Command Injection in Appointment Emails for Nextcloud Calendar (medium 5.3)
- [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)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-33183 and fix it if it is affected.

What it is: CVE-2023-33183 is a low-severity vulnerability in nextcloud security-advisories, published on 30 May 2023. 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-2023-33183 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-2023-33183/ (Markdown: https://insights.sbomify.com/CVE-2023-33183/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-33183
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-33183
- OSV: https://osv.dev/vulnerability/CVE-2023-33183

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-33183/
Summaries are generated and may contain mistakes; the official description above is the record.