Use of insufficiently random values in Siemens Nucleus DNS

1) Use of insufficiently random values

EUVDB-ID: #VU52207

Risk: Medium

CVSSv3.1: 4.6 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-27393

CWE-ID: CWE-330 - Use of Insufficiently Random Values

Exploit availability: No

Description

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

The vulnerability exists due to the DNS client does not properly randomize UDP port numbers of DNS requests. A remote attacker can poison the DNS cache or spoof DNS resolving.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Nucleus NET: All versions

Nucleus RTOS: All versions

Nucleus Source Code: All versions

VSTAR: All versions

Nucleus ReadyStart: before 2013.08

External links

http://ics-cert.us-cert.gov/advisories/icsa-21-103-14
http://cert-portal.siemens.com/productcert/txt/ssa-201384.txt

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.