CVE-2020-35684

An issue was discovered in HCC Nichestack 3.0. The code that parses TCP packets relies on an unchecked value of the IP payload size (extracted from the IP header) to compute the length of the TCP payload within the TCP checksum computation function. When the IP payload size is set to be smaller than the size of the IP header, the TCP checksum computation function may read out of bounds (a low-impact write-out-of-bounds is also possible).

• CWE-20

• https://cert-portal.siemens.com/productcert/pdf/ssa-789208.pdfMitigation, Third Party Advisory
• https://www.forescout.com/blog/new-critical-operational-technology-vulnerabilities-found-on-nichestack/Mitigation, Third Party Advisory
• https://www.hcc-embedded.comProduct
• https://www.kb.cert.org/vuls/id/608209Third Party Advisory, US Government Resource
• https://cert-portal.siemens.com/productcert/pdf/ssa-789208.pdfMitigation, Third Party Advisory
• https://www.forescout.com/blog/new-critical-operational-technology-vulnerabilities-found-on-nichestack/Mitigation, Third Party Advisory
• https://www.hcc-embedded.comProduct
• https://www.kb.cert.org/vuls/id/608209Third Party Advisory, US Government Resource

Published

Aug 19, 2021

Last Modified

Jun 17, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
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