#VU84547 Improper access control in Nextcloud Enterprise Server and Nextcloud Server - CVE-2023-49791

Vulnerability identifier: #VU84547

Vulnerability risk: Medium

CVSSv4.0: 1.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2023-49791

CWE-ID: CWE-284

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 attacker to gain unauthorized access to otherwise restricted functionality.

The vulnerability exists due to workflows do not require password confirmation on API level. A remote user can bypass implemented security restrictions and delete and modify workflows.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Nextcloud Enterprise Server: 23.0.0 - 27.1.3

Nextcloud Server: 26.0.0 - 27.1.3

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External links
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-3f8p-6qww-2prr

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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.