Bulding Firewall in Java !!!!!!!?

hi there , i hope to mack a firewall in java , i read a lot a bout firewall concept and firewall stratge but still can't how how to make the firewall monetor all conection and all ports in any machine , so if there any on can help !!!!!

Hi usama_ra,
Please go through it, so that you will get a brief idea about the firewall.
Applets are subject to heavy security constraints when executing under the control of a browser. Applets are unable to access the local file-system, to bind to local ports, or to connect to a computer via
sockets other than the computer from which the applet is loaded. While it may seem to be an annoyance for developers, there are many good reasons why such tight constraints are placed on applets.
Applets could bind to well known ports, and service network clients without authorization or consent. Applets executing within firewalls could obtain privileged information, and then send it across the
network. Applets could even be infected by viruses, such as the Java StrangeBrew strain. Applets might become infected without an applet author's knowledge and then send information back that
might leave hosts vulnerable to attack.
Signed applets may be allowed greater freedom by browsers than unsigned applets, which could be an option. In cases where an applet must be capable of network communication, HTTP can be used
as a communication mechanism. An applet could communicate via java.net.URLConnection with a CGI script, or a Java servlet. This has an added advantage - applets that use the URLConnection will be
able to communicate through a firewall.
Also please refer this URL which has a good information.
http://www.securingjava.com/chapter-five/chapter-five-5.html
I hope this will help you.
Thanks
Bakrudeen
Technical Support Engineer
Sun MicroSystems Inc, India

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Well... good; when we help each other here, we can't
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Now, then:
-- since you have reinstalled the Java Update; and
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Hello,
1) I am using the built in firewall 10.5.8, and I was wondering what functionality I will lose if I select "Block Incoming Connections" for "java".
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Thanks

1) I am using the built in firewall 10.5.8, and I was wondering what functionality I will lose if I select "Block Incoming Connections" for "java".
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2) If "Block Incoming Connections" is selected, for a specific program (java), does that mean that the program (java) will not respond to connections that the program itself opens?
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3) The icon to the left of "java" looks weird to me. Is is everyone else seeing the same icon? Here is a link to the image: http://gallery.me.com/zap1313#100057/firewall&bgcolor=black
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No.
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Hi
I am going to create a proxy firewall using Java programming language. But I don't know what tools I should use? Is there anyone who knows that? Thank you.

Hi
I am going to create a proxy firewall using Java
programming language.No you won't, pick another project.And the reason that you won't is that java is a very
poor choice if you want to write a firewall or proxy.
You should do that in e.g. C/C++ instead.
/KajNo, the reason is that he seems to have no clue about what he's trying to do and therefore likely won't succeed no matter what language he does.
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Why do you have to post the same question 3 times?
http://forum.java.sun.com/thread.jspa?threadID=652296&messageID=3834871#3834871
http://forum.java.sun.com/thread.jspa?threadID=652295&messageID=3834868#3834868
http://forum.java.sun.com/thread.jspa?threadID=620790&messageID=3498334#3498334

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You haven't downgraded the iOS or lost any features, what you've done is restored your phone from an old iOS backup.

Strange issue with 3.6.3 VPN Client and IOS firewall

I'm able to establish a VPN connection from the VPN Client to the e0/0 interface of the IOS FW/VPN router and pass encrypted traffic.
Whenever I initiate a connection to something on the "Internet" from the LAN (e0/1) of the router, a temporary ACL entry is added to ACL 103 as it should be and I'm able to get out on the Internet from the internal LAN; however, I immediately lose my VPN connection from my PC Client when IOS FW adds those temporary "return entries".
Router is running 12.2(13)T.
Anyone else having issues like that? I've looked everywhere on cisco.com and elsewhere but I don't see anyone having a similar issue.
You Cisco gurus have any thoughts?
Thanks,
Jamey
Config below:
jamey#wr t
Building configuration...
Current configuration : 3947 bytes
! Last configuration change at 16:27:03 GMT Wed Jan 22 2003 by jdepp
! NVRAM config last updated at 00:14:38 GMT Wed Jan 22 2003 by jdepp
version 12.2
service timestamps debug datetime msec
service timestamps log datetime msec localtime show-timezone
service password-encryption
hostname "jamey"
no logging buffered
no logging console
username XXXX password 7 XXXXX
clock timezone GMT 0
aaa new-model
aaa authentication login tac local
aaa session-id common
ip subnet-zero
no ip domain lookup
ip inspect name myfw ftp
ip inspect name myfw realaudio
ip inspect name myfw smtp
ip inspect name myfw streamworks
ip inspect name myfw vdolive
ip inspect name myfw tftp
ip inspect name myfw rcmd
ip inspect name myfw tcp
ip inspect name myfw udp
ip inspect name firewall http java-list 3
ip audit notify log
ip audit po max-events 100
crypto isakmp policy 3
encr 3des
hash md5
authentication pre-share
group 2
crypto isakmp nat keepalive 20
crypto isakmp client configuration group XXXX
key XXXXXXX
dns x.x.x.x
domain xxx.com
pool ipsec-pool
acl 191
crypto ipsec security-association lifetime kilobytes 536870911
crypto ipsec security-association lifetime seconds 86400
crypto ipsec transform-set foxset esp-3des esp-md5-hmac
crypto dynamic-map dynmap 10
set transform-set foxset
crypto map clientmap client authentication list tac
crypto map clientmap isakmp authorization list XXXXX
crypto map clientmap client configuration address respond
crypto map clientmap 10 ipsec-isakmp dynamic dynmap
interface Loopback10
description just for test purposes
ip address 172.16.45.1 255.255.255.0
interface Ethernet0/0
description "Internet"
ip address x.x.x.x 255.255.255.224
ip access-group 103 in
ip inspect myfw out
no ip route-cache
no ip mroute-cache
half-duplex
crypto map clientmap
interface Ethernet0/1
description "LAN"
ip address 192.168.45.89 255.255.255.0
no ip route-cache
no ip mroute-cache
half-duplex
ip local pool ipsec-pool 192.168.100.1 192.168.100.254
ip classless
ip route 0.0.0.0 0.0.0.0 Ethernet0/0
no logging trap
access-list 3 permit any
access-list 103 permit ip 192.168.100.0 0.0.0.255 any log
access-list 103 permit icmp any any log
access-list 103 permit udp any eq isakmp any log
access-list 103 permit esp any any log
access-list 103 permit ahp any any log
access-list 103 permit udp any any eq non500-isakmp log
access-list 103 permit tcp any any eq 1723 log
access-list 103 permit udp any any eq 1723 log
access-list 103 deny tcp any any log
access-list 103 deny udp any any log
access-list 191 permit ip 192.168.45.0 0.0.0.255 192.168.100.0 0.0.0.255
access-list 191 permit ip 172.16.45.0 0.0.0.255 192.168.100.0 0.0.0.255
radius-server authorization permit missing Service-Type
call rsvp-sync
line con 0
line aux 0
line vty 0 4
exec-timeout 0 0
password XXXXXX
line vty 5 15
end
Some debugging info:
At this point, my VPN PC is successfully connected to the e0/0 VPN router and assigned IP of 192.168.100.2. It is running constant pings to 192.168.45.67 and 172.16.45.1 (172.16.45.1 is a loopback on the router for testing), 192.168.45.67 is a host on the internal network.
.Jan 22 01:27:38.284: ICMP type=8, code=0
.Jan 22 01:27:38.288: IP: s=192.168.45.67 (Ethernet0/1), d=192.168.100.2 (Ethern
et0/0), g=192.168.100.2, len 60, forward
.Jan 22 01:27:38.288: ICMP type=0, code=0
.Jan 22 01:27:38.637: IP: s=192.168.45.145 (Ethernet0/0), d=255.255.255.255, len
40, access denied
.Jan 22 01:27:38.637: UDP src=2301, dst=2301
.Jan 22 01:27:38.641: IP: s=192.168.45.145 (Ethernet0/1), d=255.255.255.255, len
40, rcvd 2
.Jan 22 01:27:38.641: UDP src=2301, dst=2301
.Jan 22 01:27:38.761: IP: s=<VPN PC CLIENT> (Ethernet0/0), d=<VPN ROUTER E0/0 INTERFACE> (Ethern
et0/0), len 112, rcvd 3, proto=50
.Jan 22 01:27:38.765: IP: s=192.168.100.2 (Ethernet0/0), d=172.16.45.1, len 60,
rcvd 4
.Jan 22 01:27:38.765: ICMP type=8, code=0
.Jan 22 01:27:38.765: IP: s=172.16.45.1 (local), d=192.168.100.2 (Ethernet0/0),
len 60, sending
.Jan 22 01:27:38.765: ICMP type=0, code=0
.Jan 22 01:27:39.282: IP: s=<VPN PC CLIENT> (Ethernet0/0), d=<VPN ROUTER E0/0 INTERFACE> (Ethern
et0/0), len 112, rcvd 3, proto=50
.Jan 22 01:27:39.286: IP: s=192.168.100.2 (Ethernet0/0), d=192.168.45.67 (Ethern
et0/1), g=192.168.45.67, len 60, forward
.Jan 22 01:27:39.286: ICMP type=8, code=0
.Jan 22 01:27:39.286: IP: s=192.168.45.67 (Ethernet0/1), d=192.168.100.2 (Ethern
et0/0), g=192.168.100.2, len 60, forward
.Jan 22 01:27:39.290: ICMP type=0, code=0
.Jan 22 01:27:39.763: IP: s=<VPN PC CLIENT> (Ethernet0/0), d=<VPN ROUTER E0/0 INTERFACE> (Ethern
et0/0), len 112, rcvd 3, proto=50
.Jan 22 01:27:39.767: IP: s=192.168.100.2 (Ethernet0/0), d=172.16.45.1, len 60,
rcvd 4
.Jan 22 01:27:39.767: ICMP type=8, code=0
.Jan 22 01:27:39.767: IP: s=172.16.45.1 (local), d=192.168.100.2 (Ethernet0/0),
len 60, sending
.Jan 22 01:27:39.767: ICMP type=0, code=0
.Jan 22 01:27:40.283: IP: s=<VPN PC CLIENT> (Ethernet0/0), d=<VPN ROUTER E0/0 INTERFACE> (Ethern
et0/0), len 112, rcvd 3, proto=50
.Jan 22 01:27:40.287: IP: s=192.168.100.2 (Ethernet0/0), d=192.168.45.67 (Ethern
et0/1), g=192.168.45.67, len 60, forward
.Jan 22 01:27:40.287: ICMP type=8, code=0
.Jan 22 01:27:40.287: IP: s=192.168.45.67 (Ethernet0/1), d=192.168.100.2 (Ethern
et0/0), g=192.168.100.2, len 60, forward
.Jan 22 01:27:40.291: ICMP type=0, code=0
.Jan 22 01:27:40.596 GMT: %SEC-6-IPACCESSLOGNP: list 103 permitted 50 216.16.193
.52 -> <VPN ROUTER E0/0 INTERFACE>, 222 packets
.Jan 22 01:27:40.596 GMT: %SEC-6-IPACCESSLOGP: list 103 permitted udp 216.16.193
.52(500) -> <VPN ROUTER E0/0 INTERFACE>(500), 16 packets
here is where I initiate a telnet connection to a host 2.2.2.2 (a dummy host on the "Internet")
from a host on the internal side (LAN) (192.168.45.1)
.Jan 22 01:27:40.600: IP: s=192.168.45.1 (Ethernet0/1), d=2.2.2.2 (Ethernet0/0),
g=2.2.2.2, len 44, forward
.Jan 22 01:27:40.600: TCP src=38471, dst=23, seq=953962328, ack=0, win=4128
SYN
.Jan 22 01:27:40.764: IP: s=<VPN PC CLIENT> (Ethernet0/0), d=<VPN ROUTER E0/0 INTERFACE> (Ethern
et0/0), len 112, rcvd 3, proto=50
here is where by VPN connection breaks
.Jan 22 01:27:40.768: IPSEC(epa_des_crypt): decrypted packet failed SA identity
check
.Jan 22 01:27:41.285: IP: s=<VPN PC CLIENT> (Ethernet0/0), d=<VPN ROUTER E0/0 INTERFACE> (Ethern
et0/0), len 112, rcvd 3, proto=50
.Jan 22 01:27:41.285: IPSEC(epa_des_crypt): decrypted packet failed SA identity
check
.Jan 22 01:27:45.773: IP: s=<VPN PC CLIENT> (Ethernet0/0), d=<VPN ROUTER E0/0 INTERFACE> (Ethern
et0/0), len 112, rcvd 3, proto=50
.Jan 22 01:27:45.777: IPSEC(epa_des_crypt): decrypted packet failed SA identity
check
.Jan 22 01:27:46.774: IP: s=<VPN PC CLIENT> (Ethernet0/0), d=<VPN ROUTER E0/0 INTERFACE> (Ethern
et0/0), len 112, rcvd 3, proto=50
.Jan 22 01:27:46.774: IPSEC(epa_des_crypt): decrypted packet failed SA identity
check

Ok..I found the bug ID for this:
CSCdz46552
the workaround says to configure an ACL on the dynamic ACL.
I don't understand what that means.
I found this link:
http://www.cisco.com/en/US/products/sw/secursw/ps2138/products_maintenance_guide_chapter09186a008007da4d.html#96393
and they talk about it, but I'm having a hard time decoding what this means:
"To specify an extended access list for a crypto map entry, enter the match address crypto map configuration command. This access list determines which traffic should be protected by IPSec and which traffic should not be protected by IPSec. If this is configured, the data flow identity proposed by the IPSec peer must fall within a permit statement for this crypto access list. If this is not configured, the router will accept any data flow identity proposed by the IPSec peer. However, if this is configured but the specified access list does not exist or is empty, the router will drop all packets."

How to set proxy authentication using java properties at run time

Hi All,
How to set proxy authentication using java properties on the command line, or in Netbeans (Project => Properties
=> Run => Arguments). Below is a simple URL data extract program which works in absence of firewall:
import java.io.*;
import java.net.*;
public class DnldURLWithoutUsingProxy {
   public static void main (String[] args) {
      URL u;
      InputStream is = null;
      DataInputStream dis;
      String s;
      try {
          u = new URL("http://www.yahoo.com.au/index.html");
         is = u.openStream();         // throws an IOException
         dis = new DataInputStream(new BufferedInputStream(is));
         BufferedReader br = new BufferedReader(new InputStreamReader(dis));
      String strLine;
      //Read File Line By Line
      while ((strLine = br.readLine()) != null)      {
      // Print the content on the console
          System.out.println (strLine);
      //Close the input stream
      dis.close();
      } catch (MalformedURLException mue) {
         System.out.println("Ouch - a MalformedURLException happened.");
         mue.printStackTrace();
         System.exit(1);
      } catch (IOException ioe) {
         System.out.println("Oops- an IOException happened.");
         ioe.printStackTrace();
         System.exit(1);
      } finally {
         try {
            is.close();
         } catch (IOException ioe) {
}However, it generated the following message when run behind the firewall:
cd C:\Documents and Settings\abc\DnldURL\build\classes
java -cp . DnldURLWithoutUsingProxy
Oops- an IOException happened.
java.net.ConnectException: Connection refused
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:305)
at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:171)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:158)
at java.net.Socket.connect(Socket.java:452)
at java.net.Socket.connect(Socket.java:402)
at sun.net.NetworkClient.doConnect(NetworkClient.java:139)
at sun.net.www.http.HttpClient.openServer(HttpClient.java:402)
at sun.net.www.http.HttpClient.openServer(HttpClient.java:618)
at sun.net.www.http.HttpClient.<init>(HttpClient.java:306)
at sun.net.www.http.HttpClient.<init>(HttpClient.java:267)
at sun.net.www.http.HttpClient.New(HttpClient.java:339)
at sun.net.www.http.HttpClient.New(HttpClient.java:320)
at sun.net.www.http.HttpClient.New(HttpClient.java:315)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:510)
at sun.net.www.protocol.http.HttpURLConnection.connect(HttpURLConnection.java:487)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:615) at java.net.URL.openStream(URL.java:913) at DnldURLWithoutUsingProxy.main(DnldURLWithoutUsingProxy.java:17)
I have also tried the command without much luck either:
java -cp . -Dhttp.proxyHost=wwwproxy -Dhttp.proxyPort=80 DnldURLWithoutUsingProxy
Oops- an IOException happened.
java.io.IOException: Server returned HTTP response code: 407 for URL: http://www.yahoo.com.au/index.html
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1245) at java.net.URL.openStream(URL.java:1009) at DnldURLWithoutUsingProxy.main(DnldURLWithoutUsingProxy.java:17)
All outgoing traffic needs to use the proxy wwwproxy (alias to http://proxypac/proxy.pac) on port 80, where it will prompt for valid authentication before allowing to get through.
There is no problem pinging www.yahoo.com from this system.
I am running jdk1.6.0_03, Netbeans 6.0 on Windows XP platform.
I have tried Greg Sporar's Blog on setting the JVM option in Sun Java System Application Server (GlassFish) and
Java Control Panel - Use browser settings without success.
Thanks,
George

Hi All,
How to set proxy authentication using java properties on the command line, or in Netbeans (Project => Properties
=> Run => Arguments). Below is a simple URL data extract program which works in absence of firewall:
import java.io.*;
import java.net.*;
public class DnldURLWithoutUsingProxy {
   public static void main (String[] args) {
      URL u;
      InputStream is = null;
      DataInputStream dis;
      String s;
      try {
          u = new URL("http://www.yahoo.com.au/index.html");
         is = u.openStream();         // throws an IOException
         dis = new DataInputStream(new BufferedInputStream(is));
         BufferedReader br = new BufferedReader(new InputStreamReader(dis));
      String strLine;
      //Read File Line By Line
      while ((strLine = br.readLine()) != null)      {
      // Print the content on the console
          System.out.println (strLine);
      //Close the input stream
      dis.close();
      } catch (MalformedURLException mue) {
         System.out.println("Ouch - a MalformedURLException happened.");
         mue.printStackTrace();
         System.exit(1);
      } catch (IOException ioe) {
         System.out.println("Oops- an IOException happened.");
         ioe.printStackTrace();
         System.exit(1);
      } finally {
         try {
            is.close();
         } catch (IOException ioe) {
}However, it generated the following message when run behind the firewall:
cd C:\Documents and Settings\abc\DnldURL\build\classes
java -cp . DnldURLWithoutUsingProxy
Oops- an IOException happened.
java.net.ConnectException: Connection refused
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:305)
at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:171)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:158)
at java.net.Socket.connect(Socket.java:452)
at java.net.Socket.connect(Socket.java:402)
at sun.net.NetworkClient.doConnect(NetworkClient.java:139)
at sun.net.www.http.HttpClient.openServer(HttpClient.java:402)
at sun.net.www.http.HttpClient.openServer(HttpClient.java:618)
at sun.net.www.http.HttpClient.<init>(HttpClient.java:306)
at sun.net.www.http.HttpClient.<init>(HttpClient.java:267)
at sun.net.www.http.HttpClient.New(HttpClient.java:339)
at sun.net.www.http.HttpClient.New(HttpClient.java:320)
at sun.net.www.http.HttpClient.New(HttpClient.java:315)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:510)
at sun.net.www.protocol.http.HttpURLConnection.connect(HttpURLConnection.java:487)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:615) at java.net.URL.openStream(URL.java:913) at DnldURLWithoutUsingProxy.main(DnldURLWithoutUsingProxy.java:17)
I have also tried the command without much luck either:
java -cp . -Dhttp.proxyHost=wwwproxy -Dhttp.proxyPort=80 DnldURLWithoutUsingProxy
Oops- an IOException happened.
java.io.IOException: Server returned HTTP response code: 407 for URL: http://www.yahoo.com.au/index.html
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1245) at java.net.URL.openStream(URL.java:1009) at DnldURLWithoutUsingProxy.main(DnldURLWithoutUsingProxy.java:17)
All outgoing traffic needs to use the proxy wwwproxy (alias to http://proxypac/proxy.pac) on port 80, where it will prompt for valid authentication before allowing to get through.
There is no problem pinging www.yahoo.com from this system.
I am running jdk1.6.0_03, Netbeans 6.0 on Windows XP platform.
I have tried Greg Sporar's Blog on setting the JVM option in Sun Java System Application Server (GlassFish) and
Java Control Panel - Use browser settings without success.
Thanks,
George

How to check wether local system has blocked by firewall from program.

i am a user in my LAN area. i don't have admin rights. in our LAN few system has blocked by firewall others not blocked .
how can i check wether local host is blocked or not by firewall from java network program ?.

You can execute some kind of firewall util (if any) and parse output to receive configuration and check is address blocked or no. But if you have no admin rights - it will not help you.
Actually there is no clear way to detect was packet blocked by FW or just lost somethere.

How can I put my program behind a firewall or make it more secure?

I have a client server program and I was reading through my notes. I had jotted down a recommendation to put it behind a firewall. However, I do not know how to do this in Java at all or even where to begin. How do I even create a firewall in Java?
I'm also not sure if this is the security I need.
This program is already running inside a network limited only to certain users. However, this particular program is limited only to two users. Also, the client runs on Unix and Windows machines accesible by many users in our project. I would not know how to create a firewall for just this program and just these two users.
Right now my program is sorta like the basic client/server program examples given in the Java tutorials. It verifies the IP address of the client but like I said before anyone can be logged into that IP but only two users should be allowed to run the commands.
Would a firewall even work in this case?

However, I do not know
how to do this in Java at all or even where to begin.
How do I even create a firewall in Java? You don't.
I'm also not sure if this is the security I need.I don't think so.
I would not know how to create a firewall for just this
program and just these two users.A firewall is not for restricting access to particular users of a network. It's for keeping unauthorized people out of the network entirely. What you should do is secure the server (how to do this depends on probably many factors), and use a username and password in the client app to control access. The client contacts the server, passing the credentials, and the server either grants or denies access. It's possible you would want to hash and salt the password, depending on how secure it needs to be.

Writing a firewall

How do you write firewall software in java?
Can anyone point me to some info about creating a packet filter firewall in java.. I realise that the filtering is done on the kernel level of an OS but I have seem a few firewall programs around and was wondering how it was done.
Thanks
Sim

It is possible to write firewall in java but you should write some native code for this.
The native code should call system libraries.
There are many Linux/Java firewall builders but the Java program is actually only GUI to common filtering apps like iptables, ipchains or ipfwadm.
There are similar apps for UNIX like OS. I don't know such command-line tools to control packet filtering in Windows environment.

Java runtime plugin 14.9 is installed on my Mac 10.8, but the plugin status report from Mozilla says I need to update it. How do I resolve this?

Mozilla's plugin status report says that I need to update Java Runtime Environment, and that I am running version 14.9.0. But when I download the update, all I get is "Java 8 Update 40", which my computer says is an older version. I can't find any info on a later version than 14.9. Nor can I find this plugin in my computer -- it does not appear in the System Preferences window, or in the Applications Folder (including in Utilities). How do I clear this up? (Note: I disabled Firewall).

Hmm, Java 8 Update 40 should be the current version for both Windows and Mac. Do you recall where you got a version 14.9 -- was it part of an Apple update instead of coming from Oracle (which now operates java.com)?
I see similar threads on Apple's discussion forums but can't personally confirm whether the solutions work. For example:
* https://discussions.apple.com/thread/6857925#27894419
* https://discussions.apple.com/thread/6861354#27780165

Bulding Firewall in Java !!!!!!!?

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