fix issue 1038
add conditional check to prevent iteration over non existent list
@@ -47,6 +47,7 @@ class GCEFirewallRuleAuditor(Auditor):
Check to see if a port range exists in the allowed field.
"""
errors = []
+ if allowed_list:
for allowed in allowed_list:
ports = allowed.get('ports', None)
if ports:
