Improper Restriction of Excessive Authentication Attempts in Nextcloud Server and Enterprise Server

1) Improper Restriction of Excessive Authentication Attempts

EUVDB-ID: #VU82071

Risk: Low

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

CVE-ID: CVE-2023-45148

CWE-ID: CWE-307 - Improper Restriction of Excessive Authentication Attempts

Exploit availability: No

Description

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

The vulnerability exists due to improper rate limiter when Memcached is installed. A remote user can cause the rate limiting in Nextcloud Server could be reset unexpectedly resetting the rate count earlier than intended.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Nextcloud Enterprise Server: 22.0.0 - 27.0.2

Nextcloud Server: 25.0.0 - 27.0.2

External links

http://github.com/nextcloud/server/pull/40293
http://hackerone.com/reports/2110945
http://github.com/nextcloud/security-advisories/security/advisories/GHSA-xmhp-7vr4-hp63

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.