CVE-2025-64011: nextcloud server — Exploit

Description

Nextcloud Server 30.0.0 is vulnerable to an Insecure Direct Object Reference (IDOR) in the /core/preview endpoint. Any authenticated user can access previews of arbitrary files belonging to other users by manipulating the fileId parameter. This allows unauthorized disclosure of sensitive data, such as text files or images, without prior sharing permissions.

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CVSS v3.1 Score

4.3

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Weakness Type (CWE)

CWE-639 CWE-639

Affected Products

Vendor	Product	Versions
nextcloud	nextcloud_server	All

References

Exploits

https://drive.google.com/file/d/1eD3PN-u1caZYgGH96XHmJ7h_OBXEAHW4/view?usp=sharing https://gist.github.com/tarekramm/586dfe2d113fedfee6d71182570fc090

Other References

https://nextcloud.com

Frequently Asked Questions

What is CVE-2025-64011? +

Nextcloud Server 30.0.0 is vulnerable to an Insecure Direct Object Reference (IDOR) in the /core/preview endpoint. Any authenticated user can access previews of arbitrary files belonging to other users by manipulating the fileId parameter. This allows unauthorized disclosure of sensitive data, such as text files or images, without prior sharing permissions. It has a CVSS v3.1 base score of 4.3 (MEDIUM).

How severe is CVE-2025-64011? +

CVE-2025-64011 has a CVSS v3.1 score of 4.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2025-64011? +

CVE-2025-64011 affects products from nextcloud, specifically: nextcloud_server. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-64011? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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