Information disclosure in Nextcloud Server and Enterprise Server

1) Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

EUVDB-ID: #VU74345

Risk: Low

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

CVE-ID: CVE-2023-28835

CWE-ID: CWE-338 - Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

Exploit availability: No

Description

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to insecure randomness for default password in file sharing when password policy app is disabled. A remote user can gain unauthorized access to sensitive information on the system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Nextcloud Server: 24.0.0 - 25.0.3

Nextcloud Enterprise Server: 23.0.0 - 25.0.3

External links

http://github.com/nextcloud/server/pull/36093
http://github.com/nextcloud/security-advisories/security/advisories/GHSA-7w2p-rp9m-9xp9

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.