Hi,
On Jan 13, 2013, at 12:53 AM, Sergiu Dumitriu <sergiu(a)xwiki.org> wrote:
Hi devs,
Initially I didn't activate the resource skin extensions plugins (jsrx
and ssrx) for security considerations, since they can be used to read
any file from the classpath. I had forgotten to work on that, and now
they have been enabled and used in their current implementation for a
while. This means that changing the behavior will cause backward
incompatibilities...
So, I'm proposing that all skin resources packaged inside Jars should
reside under the /skinx/ root directory. This prefix shouldn't be
included in the pulled URL, it will be appended internally, and enforced
to prevent any /skinx/../privateresource tricks.
For example:
$xwiki.jsrx.use('/gmaps/gmaps.js')
will look for /skinx/gmaps/gmaps.js inside jars and the /classes/ directory.
As a migration plan I'd like to implement this check ASAP, add a
configuration for enabling the old behavior (if no resource was found
with the skinx prefix, search without the prefix), which should be set
to true by default in 4.5. Trigger a warning (in the logs) when such a
deprecated resource is found. For 5.0 we switch to false by default, and
in 6.0 we remove the switch completely.
WDYT?
Another solution which comes to mind is to define a java policy file and forbid access
outside the webapp root by default (allow the tmp dir, the data dir, etc). It's a bit
more complex to set up but it is also more secure for the user, more generic and I believe
we'll need to do that at some point anyway.
Thanks
-Vincent