In SIMATIC MV400 family versions prior to v7.0.6, the ISN generator is initialized with a constant value and has constant increments. An attacker could predict and hijack TCP sessions.
https://cert-portal.siemens.com/productcert/pdf/ssa-599268.pdf
Source: MITRE
Published: 2021-03-10
Updated: 2021-03-25
Type: NVD-CWE-noinfo
Base Score: 5
Vector: AV:N/AC:L/Au:N/C:N/I:P/A:N
Impact Score: 2.9
Exploitability Score: 10
Severity: MEDIUM
Base Score: 7.5
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Impact Score: 3.6
Exploitability Score: 3.9
Severity: HIGH