Don't set_port_version just from a 200 response.

Require a more positive page body match before doing that.
http://seclists.org/nmap-dev/2013/q1/304

scripts/flume-master-info.nse

@@ -149,8 +149,6 @@ action = function( host, port )
 		local body = response['body']:gsub("%%","%%%%")
 		local capacity = {}
 		stdnse.print_debug(2, ("%s: Body %s\n"):format(SCRIPT_NAME,body))
-		port.version.name = "flume-master"
-		port.version.product = "Apache Flume"
 		if body:match("Version:%s*</b>([^][,]+)") then
 			local version = body:match("Version:%s*</b>([^][,]+)")
 			stdnse.print_debug(1, ("%s: Version %s"):format(SCRIPT_NAME,version))
@@ -208,7 +206,11 @@ action = function( host, port )
 			result[#result+1] = "Config: "
 			result[#result+1] = vars
 		end
-		nmap.set_port_version(host, port)
+		if #result > 0 then
+			port.version.name = "flume-master"
+			port.version.product = "Apache Flume"
+			nmap.set_port_version(host, port)
+		end
 		return stdnse.format_output(true, result)
 	end
 end

scripts/hadoop-datanode-info.nse

@@ -48,12 +48,12 @@ action = function( host, port )
 	local response = http.get( host, port, uri )
 	stdnse.print_debug(1, ("%s: Status %s"):format(SCRIPT_NAME,response['status-line'] or "No Response"))
 	if response['status-line'] and response['status-line']:match("200%s+OK") and response['body']  then
-		port.version.name = "hadoop-datanode"
-		port.version.product = "Apache Hadoop"
-		nmap.set_port_version(host, port)
 		local body = response['body']:gsub("%%","%%%%")
 		stdnse.print_debug(2, ("%s: Body %s\n"):format(SCRIPT_NAME,body))
 		 if body:match("([^][\"]+)\">Log") then
+			port.version.name = "hadoop-datanode"
+			port.version.product = "Apache Hadoop"
+			nmap.set_port_version(host, port)
 			local logs = body:match("([^][\"]+)\">Log")
 			stdnse.print_debug(1, ("%s: Logs %s"):format(SCRIPT_NAME,logs))
 			table.insert(result, ("Logs: %s"):format(logs))

scripts/hadoop-jobtracker-info.nse

@@ -115,8 +115,6 @@ action = function( host, port )
 	stdnse.print_debug(1, ("%s: Status %s"):format(SCRIPT_NAME,response['status-line'] or "No Response"))
 	if response['status-line'] and response['status-line']:match("200%s+OK") and response['body']  then
 		stdnse.print_debug(2, ("%s: Body %s\n"):format(SCRIPT_NAME,response['body']))
-		port.version.name = "hadoop-jobtracker"
-		port.version.product = "Apache Hadoop"
 		if response['body']:match("State:</b>%s*([^][<]+)") then
 			local state = response['body']:match("State:</b>%s*([^][<]+)")
 			stdnse.print_debug(1, ("%s: State %s"):format(SCRIPT_NAME,state))
@@ -150,7 +148,6 @@ action = function( host, port )
 			stdnse.print_debug(1, ("%s: Log Files %s"):format(SCRIPT_NAME,logfiles))
 			table.insert(result, ("Log Files: %s"):format(logfiles))
 		end
-		nmap.set_port_version(host, port)
 		local tasktrackers = get_tasktrackers (host, port)
 		if next(tasktrackers) then
 			table.insert(result, "Tasktrackers: ")
@@ -161,6 +158,11 @@ action = function( host, port )
 			table.insert(result, "Userhistory: ")
 			table.insert(result, userhistory)
 		end
+		if #result > 0 then
+			port.version.name = "hadoop-jobtracker"
+			port.version.product = "Apache Hadoop"
+			nmap.set_port_version(host, port)
+		end
 		return stdnse.format_output(true, result)
 	end
 end

scripts/hadoop-namenode-info.nse

@@ -95,8 +95,6 @@ action = function( host, port )
 		local body = response['body']:gsub("%%","%%%%")
 		local capacity = {}
 		stdnse.print_debug(2, ("%s: Body %s\n"):format(SCRIPT_NAME,body))
-		port.version.name = "hadoop-namenode"
-		port.version.product = "Apache Hadoop"
 		if body:match("Started:%s*<td>([^][<]+)") then
 			local start = body:match("Started:%s*<td>([^][<]+)")
 			stdnse.print_debug(1, ("%s: Started %s"):format(SCRIPT_NAME,start))
@@ -139,7 +137,6 @@ action = function( host, port )
 			table.insert(result,"Total\tUsed (DFS)\tUsed (Non DFS)\tRemaining")
 			table.insert(result, ("%s\t%s\t%s\t%s"):format(capacity[3],capacity[4],capacity[5],capacity[6]))
 		end
-		nmap.set_port_version(host, port)
 		local datanodes_live = get_datanodes(host,port, "LIVE")
 		if next(datanodes_live) then
 			table.insert(result, "Datanodes (Live): ")
@@ -150,6 +147,11 @@ action = function( host, port )
 			table.insert(result, "Datanodes (Dead): ")
 			table.insert(result, datanodes_dead)
 		end
+		if #result > 0 then
+			port.version.name = "hadoop-namenode"
+			port.version.product = "Apache Hadoop"
+			nmap.set_port_version(host, port)
+		end
 		return stdnse.format_output(true, result)
 	end
 end

scripts/hadoop-secondary-namenode-info.nse

@@ -65,8 +65,6 @@ action = function( host, port )
 		local body = response['body']:gsub("%%","%%%%")
 		local stats = {}
 		stdnse.print_debug(2, ("%s: Body %s\n"):format(SCRIPT_NAME,body))
-		port.version.name = "hadoop-secondary-namenode"
-		port.version.product = "Apache Hadoop"
 		-- Page isn't valid html :(
 		for i in string.gmatch(body,"\n[%w%s]+:%s+[^][\n]+") do
 			table.insert(stats,i:match(":%s+([^][\n]+)"))
@@ -101,7 +99,11 @@ action = function( host, port )
 			table.insert(result, ("Checkpoint Period: %s"):format(stats[4]))
 			table.insert(result, ("Checkpoint: Size %s"):format(stats[5]))
 		end
-		nmap.set_port_version(host, port)
+		if #result > 0 then
+			port.version.name = "hadoop-secondary-namenode"
+			port.version.product = "Apache Hadoop"
+			nmap.set_port_version(host, port)
+		end
 		if target.ALLOW_NEW_TARGETS then
 			if stats[1]:match("([^][/]+)") then
 				local newtarget = stats[1]:match("([^][/]+)")

scripts/hadoop-tasktracker-info.nse

@@ -54,8 +54,6 @@ action = function( host, port )
 	if response['status-line'] and response['status-line']:match("200%s+OK") and response['body']  then
 		local body = response['body']:gsub("%%","%%%%")
 		stdnse.print_debug(2, ("%s: Body %s\n"):format(SCRIPT_NAME,body))
-		port.version.name = "hadoop-tasktracker"
-		port.version.product = "Apache Hadoop"
 		if response['body']:match("Version:</b>%s*([^][<]+)") then
 			local version = response['body']:match("Version:</b>%s*([^][<]+)")
 			local versionNo = version:match("([^][,]+)")
@@ -74,7 +72,11 @@ action = function( host, port )
 			stdnse.print_debug(1, ("%s: Logs %s"):format(SCRIPT_NAME,logs))
 			table.insert(result, ("Logs: %s"):format(logs))
 		end
-		nmap.set_port_version(host, port)
+		if #result > 0 then
+			port.version.name = "hadoop-tasktracker"
+			port.version.product = "Apache Hadoop"
+			nmap.set_port_version(host, port)
+		end
 		return stdnse.format_output(true, result)
 	end
 end

scripts/hbase-master-info.nse

@@ -67,8 +67,6 @@ action = function( host, port )
 	if response['status-line'] and response['status-line']:match("200%s+OK") and response['body']  then
 		local body = response['body']:gsub("%%","%%%%")
 		stdnse.print_debug(2, ("%s: Body %s\n"):format(SCRIPT_NAME,body))
-		port.version.name = "hbase-master"
-		port.version.product = "Apache Hadoop Hbase"
 		if body:match("HBase%s+Version</td><td>([^][<]+)") then
 			local version = body:match("HBase%s+Version</td><td>([^][<]+)"):gsub("%s+", " ")
 			stdnse.print_debug(1, ("%s:Hbase  Version %s"):format(SCRIPT_NAME,version))
@@ -127,11 +125,15 @@ action = function( host, port )
 				end
 			end
 		end
-		nmap.set_port_version(host, port)
 		if next(region_servers) then
 			table.insert(result,"Region Servers:")
 			table.insert(result,region_servers)
 		end
+		if #result > 0 then
+			port.version.name = "hbase-master"
+			port.version.product = "Apache Hadoop Hbase"
+			nmap.set_port_version(host, port)
+		end
 		return stdnse.format_output(true, result)
 	end
 end

scripts/hbase-region-info.nse

@@ -62,8 +62,6 @@ action = function( host, port )
 	if response['status-line'] and response['status-line']:match("200%s+OK") and response['body']  then
 		local body = response['body']:gsub("%%","%%%%")
 		stdnse.print_debug(2, ("%s: Body %s\n"):format(SCRIPT_NAME,body))
-		port.version.name = "hbase-region"
-		port.version.product = "Apache Hadoop Hbase"
 		if body:match("HBase%s+Version</td><td>([^][<]+)") then
 			local version = body:match("HBase%s+Version</td><td>([^][<]+)"):gsub("%s+", " ")
 			stdnse.print_debug(1, ("%s:Hbase  Version %s"):format(SCRIPT_NAME,version))
@@ -92,7 +90,11 @@ action = function( host, port )
 				end
 			end
 		end
-		nmap.set_port_version(host, port)
+		if #result > 0 then
+			port.version.name = "hbase-region"
+			port.version.product = "Apache Hadoop Hbase"
+			nmap.set_port_version(host, port)
+		end
 		return stdnse.format_output(true, result)
 	end
 end