I recently performed a Ping test and discovered that I was experiencing packet loss, or more correctly, that SpeedTest.net was unable to determine my packet status because a Java plugin was not enabled.

When I subsequently enabled the plugin, all was again right with the world. But is it?

By (re)enabling the Java plugin, have a compromised my security or malware vulnerability?

If you leave the plugin enabled, you are indeed at increased risk for malware that exploits Java vulnerabilities (assuming you cannot or have not updated the plugin and/or Java to benefit from any vulnerability fixes).

That said, however, you can always temporarily enable your browser's Java plugin whenever you are sure that the web site you visit is secure and not compromised itself. Likewise, you can temporarily enable Java to run local Java-based apps on your Mac.

Many thanks, alternate. You confirmed my concerns.

But where/how does one find the Java setting to enable & disable that plugin?

Safari Preferences/Security/Enable Plugins & Enable Java

Uncheck the options for plugins and java once done with PingTest.net

You may have to open JavaPreferences in the Applications folder to enable Java for the entire system as well....the Safari Preferences will only affect Safari)

edited to add the global turn on with JavaPreferences app....

That's where I'm confused. I am certain my OS is up to date and that Java 2012-003 is installed and that Java is enabled in Safari's preferences. But, when I go to SpeedTest.net, I am met with a note that I have an inactive Plug-in. If I then follow their prompts, I am advised that I must click on their Enable button and restart.

And then things work as designed. But since I already had Java enabled, why the extra steps?

Depending on which Safari plugins you regularly use (see Help/Installed Plug-ins) you may not want to disable all of them; disabling Java should do the trick for Flashback unless the exploit is specifically and exclusively targeted on one or more plugins.

To get the Java applet to run on my computer required enabling all the above then logging out and back in (or restarting the computer) in order to reset Safari to recognize Java.....I too got the initial warning when PingTest.net wanted to run an applet.

Hope this helps clarify things.

I logged out & in, and even restarted, but no joy.

I also checked to verify that I no longer have Click To Plugin installed (I don't).

Most strange (to me), that I am unable to get this to work. FWIW, the SpeedTest works fine.

Grrrrr…

How do you turn it on in the first place?

You may have to install Java first, as Apple no longer includes it in its latest versions of Mac OS X. See the thread How to enable the Java Plugin? for some details. For Java 7 and higher, the first link in post #32791 in that thread links to an Oracle FAQ containing a further link explaining how to enable Java in browsers running current Mac OS versions.