An administrator may attempt to block all traffic by configuring a pass filter with an empty table. However, in UBR, an empty list does not enforce any restrictions and allows all network traffic to pass unfiltered.
Exploitability
AV:NAC:LPR:HUI:NScope
S:UImpact
C:HI:NA:N4.9/CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:NOther