{
 "Type" : "AWS::EC2::SecurityGroup",
 "Properties" : {
     "GroupDescription" : "allow connections from specified source security group",
     "SecurityGroupIngress" : [
         {
            "IpProtocol" : "tcp",
            "FromPort" : "22",
            "ToPort" : "22",
            "SourceSecurityGroupName" : "myadminsecuritygroup",
            "SourceSecurityGroupOwnerId" : "123456789012"
         },
         {
            "IpProtocol" : "tcp",
            "FromPort" : "80",
            "ToPort" : "80",
            "SourceSecurityGroupName" : {"Ref" : "mysecuritygroupcreatedincfn"}
         }
     ]
 }
}