Vulnerability in Ethernut Nut\/os
CVE-2020-27213
An issue was discovered in Ethernut Nut/OS 5.1. 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. While the ISN generator seems to adhere to RFC 793 (where a global 32-bit counter is incremented roughly every 4 microseconds), proper ISN generation should aim to follow at least the specifications outlined in RFC 6528.
EPSS: 0.010 (58.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.
Affected products
- Ethernut Nut\/os — versions 5.1
- N/a — versions n/a
Weakness classification (CWE)
References
- cve@mitre.org (Release Notes)
- cve@mitre.org (Not Applicable)
- cve@mitre.org (US Government Resource, Third Party Advisory)
- cve@mitre.org (Exploit, Third Party Advisory)
Frequently asked questions
- What is CVE-2020-27213?
- CVE-2020-27213 is a high-severity vulnerability in Ethernut Nut\/os, classified under Use of Insufficiently Random Values. CVSS score: 7.5/10. Published 2023-10-10.
- How severe is CVE-2020-27213?
- High severity. CVSS v3 base score is 7.5 out of 10.