Vulnerability Description
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.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Siemens | Simatic Mv420 Firmware | < 7.0.6 |
| Siemens | Simatic Mv420 | - |
| Siemens | Simatic Mv440 Firmware | < 7.0.6 |
| Siemens | Simatic Mv440 | - |
References
- https://cert-portal.siemens.com/productcert/pdf/ssa-599268.pdfVendor Advisory
- https://www.cisa.gov/news-events/ics-advisories/icsa-21-042-01
- https://www.forescout.com/resources/numberjack-weak-isn-generation-in-embedded-t
- https://cert-portal.siemens.com/productcert/pdf/ssa-599268.pdfVendor Advisory
- https://www.cisa.gov/news-events/ics-advisories/icsa-21-042-01
- https://www.forescout.com/resources/numberjack-weak-isn-generation-in-embedded-t
FAQ
What is CVE-2020-27632?
CVE-2020-27632 is a vulnerability with a CVSS score of 7.5 (HIGH). 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.
How severe is CVE-2020-27632?
CVE-2020-27632 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2020-27632?
Check the references section above for vendor advisories and patch information. Affected products include: Siemens Simatic Mv420 Firmware, Siemens Simatic Mv420, Siemens Simatic Mv440 Firmware, Siemens Simatic Mv440.