Vulnerability Details : CVE-2020-27632
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.
Products affected by CVE-2020-27632
- cpe:2.3:o:siemens:simatic_mv420_firmware:*:*:*:*:*:*:*:*
- cpe:2.3:o:siemens:simatic_mv440_firmware:*:*:*:*:*:*:*:*
Exploit prediction scoring system (EPSS) score for CVE-2020-27632
0.11%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 43 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2020-27632
| Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
|---|---|---|---|---|---|---|
|
5.0
|
MEDIUM | AV:N/AC:L/Au:N/C:N/I:P/A:N |
10.0
|
2.9
|
NIST | |
|
7.5
|
HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
3.9
|
3.6
|
NIST |
References for CVE-2020-27632
-
https://www.forescout.com/resources/numberjack-weak-isn-generation-in-embedded-tcpip-stacks/
-
https://www.cisa.gov/news-events/ics-advisories/icsa-21-042-01
Multiple Embedded TCP/IP Stacks (Update B) | CISA
-
https://cert-portal.siemens.com/productcert/pdf/ssa-599268.pdf
Vendor Advisory
Jump to