Vulnerability in Hcc-Embedded Nichestack
CVE-2020-35685
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.)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.021 (80.5th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 80th percentile — 80.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.021 · newest: 0.021 · change: 0.000
Affected products
Weakness classification (CWE)
References
- www.hcc-embedded.com (Product)
- cert-portal.siemens.com/productcert/pdf/ssa-789208.pdf (Third Party Advisory, Mitigation)
- www.forescout.com/blog/new-critical-operational-technology-vulnerabilities-foun… (Third Party Advisory, Mitigation)
- www.kb.cert.org/vuls/id/608209 (US Government Resource, Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2020-35685?
- CVE-2020-35685 is a critical-severity vulnerability in Hcc-Embedded Nichestack, classified under Use of Insufficiently Random Values. CVSS score: 9.1/10. Published 2021-08-19.
- How severe is CVE-2020-35685?
- Critical severity. CVSS v3 base score is 9.1 out of 10.