In OpenStack Nova before 33.0.2, the server create API does not strip certain hint data. The resulting instance has no Placement allocation.
Exploitability
AV:NAC:LPR:LUI:NScope
S:UImpact
C:LI:NA:L5.4/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:LOther