How to verify that you're running Oracle's Java JRE 7 and not Apple JRE 6 Java is one of the most used programming languages, being present in a lot of devices, including our Macs. One of its strong features is its cross-system compatibility, so you only need to think in Java language and rely on the Java Runtime Environment (JRE) that need to be present in the system that intend to use the application - in Java they're called applets - you want to run. Java applications are most commonly used within a browser, using a Java plug-in, but you can also standalone applications that use the JRE. There's a lot of misunderstanding around this and Java is not only present in Safari, but rather you can say that it can be used as long as it is activated in your Mac. And being a runtime environment, a place in which the user can run software... it's exposed to a lot of security issues. I'm quite sure anyone who has a minimum contact with Apple related news has read something about Flashback, a piece of malware that appeared as Flash Player installer and installed some bad stuff in your system even if you decided not to enter the administrator password. With OS X Lion, Apple decided not to deliver the Java Runtime Environment to end users, offering a download from their servers as soon as the user need to run a piece of Java software. This is a wrong approach. Definately, you protect a lot of users, but you leave unprotected a lot of end users that need Java to run many online services: from banking to e-shopping, many websites need Java. This was even wrong because Apple offered their own implementation of the JRE version 6, while the rest of the operating systems - Windows, Linux or Solaris - run the official distribution from Oracle, now that the database giant acquired Sun. Any piece of software delivered to the end user computer need an strategy to get it updated as soon as a vulnerability surfaces. And in this case Apple did it really wrong. The exploit that let the Flashback execution could be run in any Mac after Oracle deployed the new patched 7 version, and after a lot of time, Apple didn't update it and rather decided to forget about it. Now the JRE is also available from the official website http://www.java.com for users running OS X 10.7.3 and above, but even though you have installed it, you must take care and check if Apple JRE 6 is not taking over Oracle JRE 7. Let's see how. Once you have downloaded the jre-7u6-macosx-x64.dmg file and installed it, you can go to a new icon in the new preference pane callled "Java". In the General tab you can press de About button and see that Oracle JRE 7 is installed. But if we go to Applications > Utiities > Java Preferences Sin embargo, we can see that we have also JRE 6 from Apple installed and checked. Of course, this only applies to users that have previously downloaded the Apple JRE. So, how can we know which JRE is actually being executed when we try to use a Java applet? You can use the Terminal to enter the command java -version that will bring this output: java version "1.6.0_35" Java(TM) SE Runtime Environment (build 1.6.0_35-b10-428-11M3811) Java HotSpot(TM) 64-Bit Server VM (build 20.10-b01-428, mixed mode) So even though I have Oracle's JRE 7 installed, I'm running Apple's JRE 6. And if I try to uncheck the Apple JRE 6 in the Java Preferences app, I can't run applets at all. After some reading in the Oracle website in http://www.java.com/en/download/faq/java_mac.xml I have understand what's happening, and I'll explain to you how to fix it. You can see exactly what's happening by reading http://docs.oracle.com/javase/7/docs/webnotes/install/mac/mac-preferences.html: Note for Users of Macs that Include Apple Java 6 If you are running a release of Mac OS X that includes Apple Java 6, for example 10.7.3 or 10.7.4, there is an important difference about the installation of Oracle Java (both JRE and JDK) that you should be aware of. The Applications -> Utilities -> Java Preferences application is part of Apple's implementation of Java. Once Apple no longer distributes Java as part of their release, the Java Preferences application is retired. Under Apple's implementation of Java, it was possible to have multiple JREs installed, and the Java Preferences app was used to determine the first compatible version that would be used. The following instructions show how to change the default JRE. [li]Launch Java Preferences. The Java Preferences window contains a list of installed JREs. Java applications and command line tools use the listed order to determine the first compatible version to use. The Vendor column indicates whether the Java release is supplied by Apple or Oracle. The Version column specifies the version of Java that is installed.[/li] [li]To make JRE 7 the default version of Java, re-order the list by dragging Java SE 7 to the top of the list.[/li] Note that if you install only Oracle Java JRE 7, it will not appear in this list. You must install the full JDK in order for JRE 7 to be listed. So we must install the Java Develoment Kit and not the Java Runtime Environment if we want to run the patched JRE. Even though we're not developers, but it's the only way I've seen to resolve the problem. To install the JDK you must go to http://www.oracle.com/technetwork/java/javase/downloads/jdk7u7-downloads-1836413.html and download the installer. Once installed, you will see the Oracle's version in the Java Preference app, but Apple's version is still checked, and being the first in the list it will take precedence from Oracle's version. You can drag the Oracle version and drop it into the top of the list. This way it takes precedence and I also recommend to uncheck Apple's JRE 6. Back to the Terminal app, the java -version command output inform us that we're running the correct version. java version "1.7.0_07" Java(TM) SE Runtime Environment (build 1.7.0_07-b10) Java HotSpot(TM) 64-Bit Server VM (build 23.3-b01, mixed mode) And to verify that Java applets can be run, we can go to http://java.com/es/download/installed.jsp to run a small applet that will check if we're running the correct version. In my opinion, Oracle and Apple should talk to get this totally transparent for the end user. Until then, I recommend you to verify if you're running the correct version and act accordingly so you are protected from those at least annoying security issues.