CVE-2020-35685

 

Published at: - 19-08-2021 02:15

Last modified: - 26-09-2022 12:39

Total changes: - 5

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.)

Common Vulnerability Scoring System (CVSS)

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

 

Verification logic

 

Reference

• https://cert-portal.siemens.com/productcert/pdf/ssa-789208.pdf
• https://www.hcc-embedded.com
• VU#608209-Third Party Advisory, US Government Resource
• https://www.forescout.com/blog/new-critical-operational-technology-vulnerabilities-found-on-nichestack/

 

Keywords

NVD

 

CVE-2020-35685

 

CVE

 

Common vulnerabilities & exposures

 

CVSS

 

Common vulnerability scoring system

 

Security

 

Vulnerabilities

 

Exposures