# CVE-2021-22913: Information disclosure in Nextcloud Deck

> Attackers can access sharee information via the lookup server during searches, exposing user data in Nextcloud Deck.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 11 Jun 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-h8f6-wg82-6p7r

## What is CVE-2021-22913?

CVE-2021-22913 is a medium-severity vulnerability in Nextcloud Deck, published on 11 Jun 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Nextcloud Deck before 1.2.7, 1.4.1 suffers from an information disclosure vulnerability when searches for sharees utilize the lookup server by default instead of only the local Nextcloud server unless a global search has been explicitly chosen by the user.

Weakness: CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2021-22913?

It affects 1 product.


Products: Nextcloud Deck.

## How do I fix CVE-2021-22913?

No fix has been published for CVE-2021-22913 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-22913 being exploited?

There is no known exploitation of CVE-2021-22913 in the wild and no public exploit code.

## Other vulnerabilities in Nextcloud Deck

- [CVE-2021-39225](https://insights.sbomify.com/CVE-2021-39225/): Missing permission check on Deck API (high 8.1)
- [CVE-2020-8182](https://insights.sbomify.com/CVE-2020-8182/): Missing authorization in Nextcloud Deck (high 8.0)
- [CVE-2021-37631](https://insights.sbomify.com/CVE-2021-37631/): Circle can be accessed by non-Circle members in Nextcloud Deck (medium 6.5)
- [CVE-2023-22469](https://insights.sbomify.com/CVE-2023-22469/): Nextcloud Deck card vulnerable to data leak to unauthorized users via reference preview cache (medium 5.8)
- [CVE-2025-66557](https://insights.sbomify.com/CVE-2025-66557/): Nextcloud Deck app allowed user with "Can share" permission to modify permissions of other non-owners (medium 5.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-22913 and fix it if it is affected.

What it is: CVE-2021-22913 is a medium-severity vulnerability in Nextcloud Deck, published on 11 Jun 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-22913 in the wild and no public exploit code.

Affected product: Nextcloud Deck. 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-2021-22913/ (Markdown: https://insights.sbomify.com/CVE-2021-22913/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-22913
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-22913
- OSV: https://osv.dev/vulnerability/CVE-2021-22913

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-22913/
Summaries are generated and may contain mistakes; the official description above is the record.