CVE-2020-17469

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 3.0% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2020-12-11 · updated 2026-06-17
Weakness: CWE-824

Description

An issue was discovered in FNET through 4.6.4. The code for IPv6 fragment reassembly tries to access a previous fragment starting from a network incoming fragment that still doesn't have a reference to the previous one (which supposedly resides in the reassembly list). When faced with an incoming fragment that belongs to a non-empty fragment list, IPv6 reassembly must check that there are no empty holes between the fragments: this leads to an uninitialized pointer dereference in _fnet_ip6_reassembly in fnet_ip6.c, and causes Denial-of-Service.

Affected products

Butok Fnet: through 4.6.4

References

http://fnet.sourceforge.net/manual/fnet_history.html
https://us-cert.cisa.gov/ics/advisories/icsa-20-343-01
https://www.kb.cert.org/vuls/id/815128
http://fnet.sourceforge.net/manual/fnet_history.html
https://us-cert.cisa.gov/ics/advisories/icsa-20-343-01
https://www.kb.cert.org/vuls/id/815128

Get alerted when CVE-2020-17469 or the next vulnerability affects your stack