#VU77662 Improper Restriction of Excessive Authentication Attempts in Nextcloud Enterprise Server and Nextcloud Server - CVE-2023-35172

Vulnerability identifier: #VU77662

Vulnerability risk: High

CVSSv4.0: 6.9 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2023-35172

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 within the password reset endpoint. A remote attacker can brute-force the password reset links.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Nextcloud Enterprise Server: 21.0.0 - 26.0.1

Nextcloud Server: 25.0.0 - 26.0.1

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External links
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-mjf5-p765-qmr6

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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.