receive.c in fastd before v21 allows denial of service (assertion failure) when receiving packets with an invalid type code.
bugs.debian.org/972521
fastd.readthedocs.io/en/stable/releases/v21.html
github.com/NeoRaider/fastd/commit/737925113363b6130879729cdff9ccc46c33eaea
lists.debian.org/debian-lts-announce/2020/10/msg00025.html
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/D2LNSF2LI4RQ7BVGHTJQUJWP7RVGHDTK/
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GUZ3AGTAXH7OOP45F5WXBVRQ3IDWUR7M/
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WSMH65GHKHMJAK2VMPROIPIUS4IA63CW/