title: pf incorrectly handles multiple IPv6 fragment headers
description: In pf packet processing with a 'scrub fragment reassemble' rule, a packet containing multiple IPv6 fragment headers would be reassembled, and then immediately processed.  That is, a packet with multiple fragment extension headers would not be recognized as the correct ultimate payload. Instead a packet with multiple IPv6 fragment headers would unexpectedly be interpreted as a fragmented packet, rather than as whatever the real payload is.
As a result, IPv6 fragments may bypass pf firewall rules written on the assumption all fragments have been reassembled and, as a result, be forwarded or processed by the host.
problem types: CWE-167: Improper Handling of Additional Special Element
affected:
{
defaultStatus: unknown
modules: pf
product: FreeBSD
vendor: FreeBSD
versions:
lessThan: p3, status: affected, version: 13.2-RELEASE, versionType: release
lessThan: p5, status: affected, version: 12.4-RELEASE, versionType: release
}