CVE-2021-41241: nextcloud nextcloud_server Incorrect Authorization
Vulnerability summary
CVE-2021-41241 is a medium (CVSS 4.3) Incorrect Authorization vulnerability in nextcloud nextcloud_server. EPSS estimates a 0.85% chance of exploitation in the next 30 days, higher than 57.4% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 2 · Related 2Timeline
- 08-03-2022PublishedVulnerability first disclosed.
- 23-04-2025Last modifiedVulnerability information updated.
Description
Nextcloud server is a self hosted system designed to provide cloud style services. The groupfolders application for Nextcloud allows sharing a folder with a group of people. In addition, it allows setting "advanced permissions" on subfolders, for example, a user could be granted access to the groupfolder but not specific subfolders. Due to a lacking permission check in affected versions, a user could still access these subfolders by copying the groupfolder to another location. It is recommended that the Nextcloud Server is upgraded to 20.0.14, 21.0.6 or 22.2.1. Users unable to upgrade should disable the "groupfolders" application in the admin settings.
CVSS metrics
3 scores · 2 sources · 2 versions- NVDNIST4.3MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
EPSS trend
Probability
0.85%
Chance of exploitation in the next 30 days
Percentile
57%
Versus all other CVEs
30-day change
0.00 pp
From 0.85% on 18-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-863Incorrect AuthorizationThe product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.
- CWE-862Missing AuthorizationThe product does not perform an authorization check when an actor attempts to access a resource or perform an action.
Affected systems
Nextcloud2 products
- nextcloud_serverEOL< 20.0.14 | ≥ 21.0.0, < 21.0.6 | 22.2.0
- security-advisories< 20.0.14 | ≥ 21.0.0, < 21.0.6 | ≥ 22.2.0, < 22.2.1
1 vendor · 2 products
References
4 links- github.com/nextcloud/security-advisories/security/advisories/GHSA-m4wp-r357-4q94X Refsource CONFIRMIssue TrackingThird Party Advisory
- github.com/nextcloud/groupfolders/issues/1692X Refsource MISCIssue TrackingPatchThird Party Advisory