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.
Configurations

Configuration 1 (hide)

cpe:2.3:o:ethernut:nut\/os:5.1:*:*:*:*:*:*:*

History

27 Oct 2023, 19:34

Type Values Removed Values Added
First Time Ethernut
Ethernut nut\/os
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 7.5
References (MISC) http://lists.egnite.de/mailman/listinfo/en-nut-announce - (MISC) http://lists.egnite.de/mailman/listinfo/en-nut-announce - Not Applicable
References (MISC) https://www.forescout.com/resources/numberjack-weak-isn-generation-in-embedded-tcpip-stacks/ - (MISC) https://www.forescout.com/resources/numberjack-weak-isn-generation-in-embedded-tcpip-stacks/ - Exploit, Third Party Advisory
References (MISC) https://www.cisa.gov/news-events/ics-advisories/icsa-21-042-01 - (MISC) https://www.cisa.gov/news-events/ics-advisories/icsa-21-042-01 - Third Party Advisory, US Government Resource
References (MISC) http://www.ethernut.de/en/download/index.html - (MISC) http://www.ethernut.de/en/download/index.html - Release Notes
CPE cpe:2.3:o:ethernut:nut\/os:5.1:*:*:*:*:*:*:*
CWE CWE-330

10 Oct 2023, 17:52

Type Values Removed Values Added
New CVE

Information

Published : 2023-10-10 17:15

Updated : 2024-02-28 20:33


NVD link : CVE-2020-27213

Mitre link : CVE-2020-27213

CVE.ORG link : CVE-2020-27213


JSON object : View

Products Affected

ethernut

  • nut\/os
CWE
CWE-330

Use of Insufficiently Random Values