File disclosure via unchecked preview share attributes
Published Dec 1, 2022 · Updated Apr 23, 2025
Improper access control in Nextcloud Server before 24.0.7 and version 25.0.0 allows remote authenticated users to retrieve restricted previews. The PublicPreviewController and PreviewController endpoints generated previews without checking the share permissions/download attribute. Access to a share with downloads disabled is required; images remain downloadable, while document previews disclose the first page without a watermark.
Summary
What happened
Improper access control in Nextcloud Server before 24.0.7 and version 25.0.0 allows remote authenticated users to retrieve restricted previews. The PublicPreviewController and PreviewController endpoints generated previews without checking the share permissions/download attribute. Access to a share with downloads disabled is required; images remain downloadable, while document previews disclose the first page without a watermark.
The record
- CVE
- CVE-2022-41970
- Published
- Dec 1, 2022
- Updated
- Apr 23, 2025
- Vendor
- Nextcloud GmbH
- Product
- Security Advisories
- Classifications
- CWE-284, CWE-863, T1530
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Dec 1, 2022CVE publishedPublication date reported by the CVE source.
- Apr 23, 2025Record 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=< 24.0.7
- Affected versionversion=>= 25.0.0, < 25.0.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
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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