CVE-2024-6640

Description

In ICMPv6 Neighbor Discovery (ND), the ID is always 0. When pf is configured to allow ND and block incoming Echo Requests, a crafted Echo Request packet after a Neighbor Solicitation (NS) can trigger an Echo Reply. The packet has to come from the same host as the NS and have a zero as identifier to match the state created by the Neighbor Discovery and allow replies to be generated. ICMPv6 packets with identifier value of zero bypass firewall rules written on the assumption that the incoming packets are going to create a state in the state table.

Reserved 2024-07-10 | Published 2024-08-11 | Updated 2024-11-26 | Assigner freebsd

Product status

Default status
unknown

14.1-RELEASE before p3
affected

14.0-RELEASE before p9
affected

13.3-RELEASE before p5
affected

Credits

Enrico Bassetti e.bassetti@tudelft.nl (Cybersecurity @ TU Delft, SPRITZ Group @ UniPD) finder

References

security.freebsd.org/advisories/FreeBSD-SA-24:05.pf.asc vendor-advisory

cve.org (CVE-2024-6640)

nvd.nist.gov (CVE-2024-6640)

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