SecurityManager environments

Robert Muir rcmuir at
Sun Apr 9 22:15:44 UTC 2017

I dont agree with the use of the word ephemeral here, thats misleading.
Those permissions are *not* needed for outgoing connections.

The default security policy of java absolutely allows for backdoors in
server applications. It does not matter if port number is 80 or 8000 the
effect is the same.

On Apr 7, 2017 6:59 AM, "Alan Bateman" <Alan.Bateman at> wrote:

> On 07/04/2017 03:54, Robert Muir wrote:
> :
>> Because of these problems, if you are a server-side app, even if you
>> understand this stuff and want to do the right thing, its really hard
>> to avoid simply granting all kinds of horrible permissions globally to
>> all code. In my experience the worst problems are the internal api
>> usage issues, so it would be nice to "give jigsaw a chance" to see if
>> it makes the situation better. SecurityManager is really great if you
>> want to prevent common security issues such as directory traversal,
>> but its too hard for a server side app right now.
> I agree with most of what you said in this mail. On "common java libraries
> don't care about this stuff" then I think part of it is that the security
> manager is not enabled by default so it's a completely different mode of
> execution and so rarely tested by many library maintainers. Also to get the
> permissions right requires understanding each of the privileged operations
> that the library might need to do and putting that code in a privileged
> block so that the library can be granted the permission rather than to
> everyone.
> On your gripes with default policy, the "bogus crap" as you termed it :-).
> It grants read access to a number of system properties and allows
> applications to bind to ephemeral ports, that's it. It used to grant
> "stopThread" (for compatibility reasons detailed in the comments) but this
> is no longer the case in JDK 9.
> It may be that this thread should move to security-dev as that is the
> right place to discuss usability and other issues with the security manager.
> -Alan.

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