Vulnerability Description
An issue was discovered in HCC Nichestack 3.0. The code that generates Initial Sequence Numbers (ISNs) for TCP connections derives the ISN from an insufficiently random source. As a result, an attacker may be able to determine the ISN of current and future TCP connections and either hijack existing ones or spoof future ones. (Proper ISN generation should aim to follow at least the specifications outlined in RFC 6528.)
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Hcc-Embedded | Nichestack | 3.0 |
| Siemens | Sentron 3Wa Com190 Firmware | < 2.0.0 |
| Siemens | Sentron 3Wa Com190 | - |
| Siemens | Sentron 3Wl Com35 Firmware | < 1.2.0 |
| Siemens | Sentron 3Wl Com35 | - |
Related Weaknesses (CWE)
References
- https://cert-portal.siemens.com/productcert/pdf/ssa-789208.pdfMitigationThird Party Advisory
- https://www.forescout.com/blog/new-critical-operational-technology-vulnerabilitiMitigationThird Party Advisory
- https://www.hcc-embedded.comProduct
- https://www.kb.cert.org/vuls/id/608209Third Party AdvisoryUS Government Resource
- https://cert-portal.siemens.com/productcert/pdf/ssa-789208.pdfMitigationThird Party Advisory
- https://www.forescout.com/blog/new-critical-operational-technology-vulnerabilitiMitigationThird Party Advisory
- https://www.hcc-embedded.comProduct
- https://www.kb.cert.org/vuls/id/608209Third Party AdvisoryUS Government Resource
FAQ
What is CVE-2020-35685?
CVE-2020-35685 is a vulnerability with a CVSS score of 9.1 (CRITICAL). An issue was discovered in HCC Nichestack 3.0. The code that generates Initial Sequence Numbers (ISNs) for TCP connections derives the ISN from an insufficiently random source. As a result, an attacke...
How severe is CVE-2020-35685?
CVE-2020-35685 has been rated CRITICAL with a CVSS base score of 9.1/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2020-35685?
Check the references section above for vendor advisories and patch information. Affected products include: Hcc-Embedded Nichestack, Siemens Sentron 3Wa Com190 Firmware, Siemens Sentron 3Wa Com190, Siemens Sentron 3Wl Com35 Firmware, Siemens Sentron 3Wl Com35.