1) Use of insufficiently random values

Risk: Medium

CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C] [PCI]

CVE-ID: CVE-2020-28388

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 ISN generator relies on a combination of values that can be inferred from a network capture. A remote attacker can interfere with traffic, spoof the connection and gain access to sensitive information.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Nucleus NET: 4.3

Nucleus ReadyStart: before 2012.12

CPE

• cpe:2.3:a:siemens:nucleus_net:4.3:*:*:*:*::*:*
• cpe:2.3:a:siemens:nucleus_readystart:*:*:*:*:*:*:*:*

External links

https://cert-portal.siemens.com/productcert/pdf/ssa-362164.pdf
https://www.forescout.com/company/blog/numberjack-forescout-research-labs-finds-nine-isn-generation-vulnerabilities-affecting-tcpip-stacks/

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.