CVE-2021-41239
User enumeration setting not respected in Nextcloud server
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
User enumeration setting not respected in Nextcloud server
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.
- Record
CVE-2021-41239- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-200
- Updated
- 2026-11-02
EUVDEUVD-2021-28293
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.
- Record
EUVD-2021-28293- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Updated
- 2026-11-02
NVD
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.
- Record
CVE-2021-41239- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:P/I:N/A:N - Weakness
- CWE-200, CWE-862
- Updated
- 2026-11-02
OSV
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.
- Record
CVE-2021-41239- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Updated
- 2026-11-02
OSVopenSUSE-SU-2022:0089-1 No score
Security update for nextcloud
This update for nextcloud fixes the following issues:
nextcloud was updated to 21.0.9:
- CVE-2021-41239 (CWE-200): user enumeration setting not obeyed in User Status API (boo#1196905)
- CVE-2021-41241 (CWE-863): groupfolders advanced permissions is not obeyed for subfolders (boo#1196908)
- CVE-2021-41741 (CWE-400): High memory usage for generating preview of broken image (boo#1196952)
- For more changes see https://nextcloud.com/changelog/#21-0-9
- Record
openSUSE-SU-2022:0089-1- Updated
- 2026-11-02
OSVopenSUSE-SU-2022:0098-1 No score
Security update for nextcloud
This update for nextcloud fixes the following issues:
nextcloud was updated to 21.0.9:
- CVE-2021-41239 (CWE-200): user enumeration setting not obeyed in User Status API (boo#1196905)
- CVE-2021-41241 (CWE-863): groupfolders advanced permissions is not obeyed for subfolders (boo#1196908)
- CVE-2021-41741 (CWE-400): High memory usage for generating preview of broken image (boo#1196952)
- For more changes see https://nextcloud.com/changelog/#21-0-9
- Record
openSUSE-SU-2022:0098-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
nextcloudSUSE:Package Hub 12 From an advisory covering 3 CVEs |
before 21.0.9-37.1 | 21.0.9-37.1 |
nextcloudSUSE:Package Hub 15 SP3 From an advisory covering 3 CVEs |
before 21.0.9-bp153.2.12.1 | 21.0.9-bp153.2.12.1 |
nextcloudopenSUSE:Leap 15.3 From an advisory covering 3 CVEs |
before 21.0.9-bp153.2.12.1 | 21.0.9-bp153.2.12.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-41239 is a medium vulnerability (CVSS 5.3) in Nextcloud Server, published March 8, 2022. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.25%, the 69th percentile. No source names a fixed version.
References
github.com/nextcloud/security-advisories/security/advisories/GHSA-g722-cm3h-8wrx
security.gentoo.org/glsa/202208-17
lists.opensuse.org/archives/list/[email protected]/thread/LRMAMGLMCXJ2VKQZRQSKAEGDMPY3MZN7
bugzilla.suse.com/1196905