Unauthorized file access via unmasked reshare permissions
Published Jul 12, 2021 · Updated Aug 3, 2024
Incorrect inherited permissions in Nextcloud Server allow remote authenticated users to expose files and folders through federated reshares. The reshareRequested method reuses a share's permission bits without intersecting them with the core shareapi_default_permissions mask. An authenticated user who can reshare a federated item can retain permissions that the server default disables, exposing only that reshared file or folder.
Summary
What happened
Incorrect inherited permissions in Nextcloud Server allow remote authenticated users to expose files and folders through federated reshares. The reshareRequested method reuses a share's permission bits without intersecting them with the core shareapi_default_permissions mask. An authenticated user who can reshare a federated item can retain permissions that the server default disables, exposing only that reshared file or folder.
The record
- CVE
- CVE-2021-32725
- Published
- Jul 12, 2021
- Updated
- Aug 3, 2024
- Vendor
- Nextcloud GmbH
- Product
- Security Advisories
- Classifications
- CWE-277, CWE-276, CAPEC-127, CAPEC-1, CAPEC-81, T1530
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 12, 2021CVE publishedPublication date reported by the CVE source.
- Aug 3, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 19.0.13
- Affected versionversion=>= 20.0.0, < 20.0.11
- Affected versionversion=>= 21.0.0, < 21.0.3
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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