CVEvulnerability
CVE-2020-35685
9.1 CRITICAL
Official page ↗
- Status
- Modified
- Published
- 2021-08-19
- Last modified
- 2026-06-17
- Assigner
- [email protected]
- CVSS 3.1 ([email protected])
- 9.1 CRITICAL — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
- CVSS 2.0 ([email protected])
- 6.4 MEDIUM — AV:N/AC:L/Au:N/C:P/I:P/A:N
- Weaknesses
- CWE-330
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.)
Affected configurations
• hcc-embedded nichestack 3.0
• siemens sentron 3wa com190 firmware (< 2.0.0)
• siemens sentron 3wl com35 firmware (< 1.2.0)
Related
Weakness · CWE (1)
- CWE-330 Use of Insufficiently Random Values weakness
References
- https://cert-portal.siemens.com/productcert/pdf/ssa-789208.pdf Mitigation, Third Party Advisory
- https://www.forescout.com/blog/new-critical-operational-technology-vulnerabilities-found-on-nichestack/ Mitigation, Third Party Advisory
- https://www.hcc-embedded.com Product
- https://www.kb.cert.org/vuls/id/608209 Third Party Advisory, US Government Resource
- https://cert-portal.siemens.com/productcert/pdf/ssa-789208.pdf Mitigation, Third Party Advisory
- https://www.forescout.com/blog/new-critical-operational-technology-vulnerabilities-found-on-nichestack/ Mitigation, Third Party Advisory
- https://www.hcc-embedded.com Product
- https://www.kb.cert.org/vuls/id/608209 Third Party Advisory, US Government Resource