Vulnerability identifier: #VU74347

Vulnerability risk: Low

CVSSv3.1: 2.1 [CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:N/I:N/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2023-28833

CWE-ID: CWE-657

Exploitation vector: Network

Exploit availability: No

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

Vendor: Nextcloud

Description

The vulnerability allows a remote user to compromise the target system.

The vulnerability exists due to violation of secure design principles. A remote administrator has ability to control the filename when uploading a logo or favicon in the theming settings.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Nextcloud Enterprise Server: 23.0.0 - 25.0.3

Nextcloud Server: 24.0.0 - 25.0.3

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External links
http://github.com/nextcloud/server/pull/36095
http://github.com/nextcloud/security-advisories/security/advisories/GHSA-ch7f-px7m-hg25

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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.