Vulnerability identifier: #VU74599

Vulnerability risk: Low

CVSSv3.1: 3.8 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2023-28834

CWE-ID: CWE-200

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 access to potentially sensitive information.

The vulnerability exists due to excessive data output by the application. A remote user can obtain the full data directory path of the Nextcloud server from an API endpoint.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Nextcloud Server: 23.0.0 - 25.0.5

Nextcloud Enterprise Server: 23.0.0 - 25.0.3

---

External links
http://github.com/nextcloud/server/issues/33883
http://hackerone.com/reports/1690510
http://github.com/nextcloud/server/pull/36094
http://github.com/nextcloud/security-advisories/security/advisories/GHSA-5w64-6c42-rgcv

---

Q & A

Can this vulnerability be exploited remotely?

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

Is there known malware, which exploits this vulnerability?

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