#VU83357 Improper access control in Nextcloud Server and Nextcloud Enterprise Server - CVE-2023-48303

Vulnerability identifier: #VU83357

Vulnerability risk: Low

CVSSv4.0: 0.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2023-48303

CWE-ID: CWE-284

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Nextcloud Server
Client/Desktop applications / Messaging software
Nextcloud Enterprise Server
Client/Desktop applications / Messaging software

Vendor: Nextcloud

Description

The vulnerability allows a remote user to gain unauthorized access to otherwise restricted functionality.

The vulnerability exists due to improper access restrictions. A remote administrator can change authentication details of user configured external storage.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Nextcloud Server: 25.0.0 - 27.0.2

Nextcloud Enterprise Server: 25.0.0 - 27.0.2

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External links
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-2448-44rp-c7hh

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated privileged user via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.