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.)
The product uses insufficiently random numbers or values in a security context that depends on unpredictable numbers.
| Link | Tags |
|---|---|
| https://www.hcc-embedded.com | product |
| 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.kb.cert.org/vuls/id/608209 | third party advisory us government resource |