#VU74117 Improper Restriction of Excessive Authentication Attempts in Nextcloud Enterprise Server and Nextcloud Server - CVE-2023-25818

Vulnerability identifier: #VU74117

Vulnerability risk: Medium

CVSSv4.0: 1.7 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2023-25818

CWE-ID: CWE-307

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 compromise the target system.

The vulnerability exists due to missing brute force protection on password reset token. A remote attacker can reset the password of another user.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Nextcloud Enterprise Server: 21.0.9.0 - 25.0.3

Nextcloud Server: 24.0.0 - 25.0.3

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External links
https://github.com/nextcloud/server/pull/36489
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-v243-x6jc-42mp
https://github.com/nextcloud/server/pull/36489/commits/704eb3aa6cecc0a646f5cca4290b595f493f9ed3

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

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