PA should probably update the help file for these vulnerability options. The wording is ambiguous and I assume that block was a drop and not a reset action. Action Choose the action (Alert, Allow, Default, or Block) to take when the rule is triggered. The Default action is based on the pre-defined action that is part of each signature provided by Palo Alto Networks. To view the default action for a signature, navigate to Objects > Security Profiles > Vulnerability Protection and click Add or select an existing profile. Click the Exceptions tab and then click Show all signatures. A list of all signatures will displayed and you will see an Action column.
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