CVE-2020-17468: Butok Fnet

High severity, CVSS 7.5. EPSS: 3% chance of exploitation in the next 30 days.

An issue was discovered in FNET through 4.6.4. The code for processing the hop-by-hop header (in the IPv6 extension headers) doesn't check for a valid length of an extension header, and therefore an out-of-bounds read can occur in _fnet_ip6_ext_header_handler_options in fnet_ip6.c, leading to Denial-of-Service.

Affected products

• Butok Fnet: up to and including 4.6.4

Published 2020-12-11. Last modified 2026-06-17.