Um... So what I said is that the @ thing is not part of a public API
*currently*, but the other parts are. The main reason of that is that the
"rules" (i.e., "whitelistPolicyIfAssignable" and
"blacklistUnlistedMembers") are some ad hoc hacks to make a less unsafe but
still mostly backward compatible version of the legacy member access rules.
So I assumed they are not very useful outside of that. Also, I wouldn't
commit to anything until I have some feedback about what
MemberAccessPolicy-es will people need, what's the good practice, etc.
Because, once something is added to public API, it stays (almost) forever.
So for now I though we will see if whitelist with the TemplatAccessible
annotations will be good enough, and when it's not, why not. So I'm
interested in what rules you need (if you do need such things, but I guess
so from what you said), or why else do yo need that part of the syntax.

On Thu, Jan 23, 2020 at 1:46 PM Christoph Rüger <[email protected]>
wrote:

> Am Mi., 22. Jan. 2020 um 21:51 Uhr schrieb Daniel Dekany <
> [email protected]>:
>
> > Off hand, I have no objections. Though I don't yet know exactly how you
> > imagine it. MemberSelector.parse and MemberSelector.isIgnoredLine are
> > public.
>
>
>
> > The "@" <rule> <upperBoundType> syntax parsing is not public.
>
> I see.
>
>
> > Do
> > you intend to use that in your application?
> >
>
> My naive thought was "cool there is already a textual format which let me
> maintain a list. So I just create a similar file and adapt it to our needs
> instead of reinventing the wheel".
>
> Ok, if this is not meant to be public we can build our own.
>
>
>
> >
> > On Wed, Jan 22, 2020 at 12:45 AM Christoph Rüger <[email protected]>
> > wrote:
> >
> > > Daniel, do you have any objections to refactoring the file-parsing-code
> > in
> > > DefaultMemberAccessPolicy to be reusable? e.g. to use it against an own
> > > file which is structured like DefaultMemberAccessPolicy-rules? Even
> when
> > > using WhitelistMemberAccessPolicy it would be great to maintain this
> in a
> > > file like DefaultMemberAccessPolicy-rules
> > >
> > > Sure, one could write own logic like this, but why not built upon this
> > one
> > > if someone wants to maintain the list in a text file.
> > >
> > >
> > > Am Do., 16. Jan. 2020 um 23:07 Uhr schrieb Christoph Rüger <
> > > [email protected]>:
> > >
> > > >
> > > > Am Do., 16. Jan. 2020 um 07:49 Uhr schrieb Daniel Dekany <
> > > > [email protected]>:
> > > >
> > > >> Quick idea... What if you create a MemberAccessPolicy implementation
> > > that
> > > >> just delegates to the actual WhiltlistAccessPolicy, which is in an
> > > >> AtomicReference field. When something registers a new piece a
> > whitelist,
> > > >> you fully recreate this embedded WhitelistAcessPolicy. I guess such
> > even
> > > >> would be rare considering the whole lifecycle of the application.
> > > >>
> > > >
> > > > Good idea, thanks.
> > > >
> > > >
> > > >>
> > > >> On Wed, Jan 15, 2020 at 9:47 AM Christoph Rüger <
> [email protected]
> > >
> > > >> wrote:
> > > >>
> > > >> > First of all, great stuff. Also thanks for
> > > >> > making BeansWrapper.invokeMethod(Object, Method, Object[])
> > protected,
> > > as
> > > >> > this helps us to monitor method invocations. As you write in a
> > comment
> > > >> it
> > > >> > will be "significant work to put together" a whitelist, but this
> > will
> > > >> help
> > > >> > to do so. Do you think it makes sense to provide a helper method
> > e.g.
> > > >> > public String MemberSelector.toSelectorRulesString() which
> outputs a
> > > >> String
> > > >> > which is understood by MemberSelector.parse(String)? Could be
> > helpful
> > > >> for
> > > >> > monitoring in that context to make sure you create such rules
> > > (strings)
> > > >> and
> > > >> > always get the syntax right.
> > > >> >
> > > >> > Am Di., 14. Jan. 2020 um 23:40 Uhr schrieb Daniel Dekany <
> > > >> > [email protected]>:
> > > >> >
> > > >> > > And updated it again... I hope I won't find any more things I
> > missed
> > > >> to
> > > >> > > address.
> > > >> > >
> > > >> > > Anyway, I think we should start going for a release (in a month
> or
> > > >> > > something), so, Christoph, any idea when can you say something
> > about
> > > >> the
> > > >> > > OSGi issues? I don't want to release something where that can't
> be
> > > >> > solved.
> > > >> > >
> > > >> >
> > > >> >
> > > >> > I had a first look at it and try to wrap my head around it.
> > > >> > Regarding OSGI: I noticed that a Classloader can be passed to e.g.
> > > >> > MemberSelector.parse(Collection<String>, boolean, ClassLoader)
> which
> > > is
> > > >> > always a good thing for OSGI.
> > > >> >
> > > >> > The key thing in OSG is that new Classes (provided by bundles) can
> > > >> appear
> > > >> > dynamically at runtime at any point in time. So I think we would
> > need
> > > to
> > > >> > add rules to MemberAccessPolicy dynamically. Since
> > > >> > MemberSelectorListMemberAccessPolicy.forClass(Class<?>) is made
> > final
> > > I
> > > >> > assume we need to write our own MemberAccessPolicy from scratch
> (or
> > > >> > duplicate code from MemberSelectorListMemberAccessPolicy) in order
> > to
> > > >> add
> > > >> > MemberSelectors dynamically. Right? Or would it be possible to
> > somehow
> > > >> > extend MemberSelectorListMemberAccessPolicy /
> > > >> WhitelistMemberAccessPolicy
> > > >> > and add MemberSelectors to the internal matchers (e.g.
> MethodMatcher
> > > >> etc.)
> > > >> > from a subclass?
> > > >> >
> > > >> > I guess we would like to subclass WhitelistMemberAccessPolicy to
> > > handle
> > > >> > dynamic registration of our OSGI stuff (means adding
> MemberSelectors
> > > >> > dynamically).
> > > >> >
> > > >> > It might be too early as I have not fully understood everything,
> but
> > > >> maybe
> > > >> > you can provide first thoughts.
> > > >> >
> > > >> >
> > > >> >
> > > >> >
> > > >> > > On Sat, Jan 11, 2020 at 8:25 PM Daniel Dekany <
> > > >> [email protected]>
> > > >> > > wrote:
> > > >> > >
> > > >> > > > I have also updated the default member access policy, so the
> > > tricks
> > > >> you
> > > >> > > > tried back then shouldn't work anymore, even if you don't use
> > your
> > > >> own
> > > >> > > > member access policy. But, you still definitely should use
> your
> > > own
> > > >> > > policy,
> > > >> > > > if users aren't trusted.
> > > >> > > >
> > > >> > > > The other API-s and Javadocs were evolved too a bit since
> then;
> > I
> > > >> have
> > > >> > > > deployed it to the maven repo and updated
> > > >> > > > https://freemarker.apache.org/builds/fm2
> > > >> > > > <
> > > >> > >
> > > >> >
> > > >>
> > >
> >
> https://freemarker.apache.org/builds/fm2/api/freemarker/ext/beans/MemberAccessPolicy.html
> > > >> > > >
> > > >> > > >  accordingly,
> > > >> > > >
> > > >> > > >
> > > >> > > > On Thu, Jan 2, 2020 at 10:55 PM Christoph Rüger <
> > > >> [email protected]>
> > > >> > > > wrote:
> > > >> > > >
> > > >> > > >> Am Mi., 1. Jan. 2020 um 22:12 Uhr schrieb Daniel Dekany <
> > > >> > > >> [email protected]>:
> > > >> > > >>
> > > >> > > >> > Guys,
> > > >> > > >> >
> > > >> > > >> > I have add MemberAccessPolicy to the API, which you can
> plug
> > > >> into a
> > > >> > > >> > DefaultObjectWrapper (or to any BeansWrapper). I have also
> > > added
> > > >> > > >> > WhitelistMemberAccessPolicy, to ease adding a restrictive
> > > policy.
> > > >> > > Please
> > > >> > > >> > take a look. 2.3.30-SNAPSHOT is in the Apache snapshot
> repo,
> > as
> > > >> > usual.
> > > >> > > >> You
> > > >> > > >> > can start out from here in API documentation:
> > > >> > > >> >
> > > >> > > >> >
> > > >> > > >>
> > > >> > >
> > > >> >
> > > >>
> > >
> >
> https://freemarker.apache.org/builds/fm2/api/freemarker/ext/beans/MemberAccessPolicy.html
> > > >> > > >>
> > > >> > > >>
> > > >> > > >> Thanks Daniel and happy new year :)
> > > >> > > >> We will try to test this. Cannot promise how soon we get to
> it,
> > > >> but I
> > > >> > > will
> > > >> > > >> try my best.
> > > >> > > >> We will also check how this behaves in our OSGI world.
> > > >> > > >>
> > > >> > > >>
> > > >> > > >> >
> > > >> > > >> >
> > > >> > > >> > So please review these, tell if you have any
> recommendations,
> > > or
> > > >> you
> > > >> > > >> see a
> > > >> > > >> > way to circumvent this. (One risky thing I see is that we
> > have
> > > a
> > > >> > long
> > > >> > > >> > deprecated default static instance of DefaultObjectWrapper,
> > > >> which if
> > > >> > > >> course
> > > >> > > >> > doesn't use any custom MemberAccessPolicy. We use that
> static
> > > >> > instance
> > > >> > > >> > internally in FM2 on a lot of places. I will have to review
> > all
> > > >> such
> > > >> > > >> cases,
> > > >> > > >> > and also make it less probable that they can become
> > exploitable
> > > >> > > later.)
> > > >> > > >> >
> > > >> > > >> > I will also create a new implementation for
> > > >> > DefaultMemberAccessPolicy
> > > >> > > >> > later. The current one does exactly what the old one did.
> The
> > > >> only
> > > >> > > real
> > > >> > > >> > solution will be still WhitelistMemberAccessPolicy, if
> > someone
> > > >> > indeed
> > > >> > > >> > doesn't trust the template authors.
> > > >> > > >> >
> > > >> > > >> > On Tue, Dec 24, 2019 at 6:31 PM Siegfried Goeschl <
> > > >> > > >> > [email protected]> wrote:
> > > >> > > >> >
> > > >> > > >> > > HI Daniel,
> > > >> > > >> > >
> > > >> > > >> > > Would it make sense to come up with a separate chapter
> for
> > > the
> > > >> > > >> existing
> > > >> > > >> > > FreeMarker documentation to explain the things in detail?
> > > >> > > >> > >
> > > >> > > >> > > Thanks in advance,
> > > >> > > >> > >
> > > >> > > >> > > Siegfried Goeschl
> > > >> > > >> > >
> > > >> > > >> > > PS: Last email for today - preparing Christmas dinner :-)
> > > >> > > >> > >
> > > >> > > >> > > > On 24.12.2019, at 18:23, Daniel Dekany <
> > > >> [email protected]
> > > >> > >
> > > >> > > >> > wrote:
> > > >> > > >> > > >
> > > >> > > >> > > > I responded to your mail that says "The problem
> described
> > > in
> > > >> the
> > > >> > > >> > article
> > > >> > > >> > > > was less about arbitrary people but someone who hacked
> > > >> through
> > > >> > > other
> > > >> > > >> > > > security issues to become administrator with temple
> > editing
> > > >> > > rights".
> > > >> > > >> > So I
> > > >> > > >> > > > thought that the premise there was that people who
> > > shouldn't
> > > >> be
> > > >> > > >> able to
> > > >> > > >> > > > edit templates become able to do so. But it doesn't
> mater
> > > >> how it
> > > >> > > >> was in
> > > >> > > >> > > > that case. Because as I said in the linked bug report,
> > and
> > > as
> > > >> > the
> > > >> > > >> FAQ
> > > >> > > >> > > says,
> > > >> > > >> > > > if you allow someone to edit templates with the default
> > > >> > FreeMarker
> > > >> > > >> > > > configuration, that's almost like if you allow them to
> > edit
> > > >> Java
> > > >> > > >> files.
> > > >> > > >> > > So
> > > >> > > >> > > > whatever your application has right to do (like read
> the
> > > >> > password
> > > >> > > >> file,
> > > >> > > >> > > > launch missiles, etc.), the templates probably can do
> as
> > > >> well.
> > > >> > The
> > > >> > > >> > point
> > > >> > > >> > > of
> > > >> > > >> > > > discouraging complex/technical logic in templates (not
> > just
> > > >> in
> > > >> > > >> > > FreeMarker)
> > > >> > > >> > > > was the MVC principle, where you should only put
> > > presentation
> > > >> > > logic
> > > >> > > >> > into
> > > >> > > >> > > > the templates.
> > > >> > > >> > > >
> > > >> > > >> > > > We can't provide a practically useful default
> > configuration
> > > >> > that's
> > > >> > > >> > secure
> > > >> > > >> > > > if you can't trust people that can edit templates,
> > because
> > > >> the
> > > >> > > >> > whitelist
> > > >> > > >> > > > content is specific to the concrete application. By
> > default
> > > >> ?new
> > > >> > > is
> > > >> > > >> not
> > > >> > > >> > > > restricted (well, it can instantiate TemplatModel-s
> only,
> > > but
> > > >> > that
> > > >> > > >> > hardly
> > > >> > > >> > > > saves anyone security wise). The reason ?api is still
> > > >> disabled
> > > >> > by
> > > >> > > >> > default
> > > >> > > >> > > > is that if someone went through the pain of setting up
> > > >> > FreeMarker
> > > >> > > >> to be
> > > >> > > >> > > > safe(r) (which implies that you do not use the default
> > > >> > > >> ObjectWrapper,
> > > >> > > >> > nor
> > > >> > > >> > > > the default settings for ?new, and you are thoughtful
> > with
> > > >> your
> > > >> > > >> > > > TemplateLoader, as the FAQ says), then the new
> FreeMarker
> > > >> > version
> > > >> > > >> where
> > > >> > > >> > > > ?api was introduced should not open a new hole on your
> > > >> system.
> > > >> > For
> > > >> > > >> > almost
> > > >> > > >> > > > all users though, ?api enabled by default would be
> better
> > > >> (it's
> > > >> > > >> mostly
> > > >> > > >> > to
> > > >> > > >> > > > allow users to work around TemplateHashModel
> limitations
> > > when
> > > >> > > >> dealing
> > > >> > > >> > > with
> > > >> > > >> > > > java.util.Map-s), but I have chosen the safer approach
> > > when I
> > > >> > > added
> > > >> > > >> it.
> > > >> > > >> > > >
> > > >> > > >> > > > The unsafeMethods mechanism will be updated, as things
> > > stand,
> > > >> > > >> despite
> > > >> > > >> > > that
> > > >> > > >> > > > it's not strictly backward compatible. It will be
> still a
> > > >> quite
> > > >> > > >> > pointless
> > > >> > > >> > > > mechanism. I don't know why was it added by the author
> > > (some
> > > >> > 10-15
> > > >> > > >> > years
> > > >> > > >> > > > ago, I think).
> > > >> > > >> > > >
> > > >> > > >> > > > On Tue, Dec 24, 2019 at 4:14 PM Siegfried Goeschl <
> > > >> > > >> > > > [email protected]> wrote:
> > > >> > > >> > > >
> > > >> > > >> > > >> Hi Daniel,
> > > >> > > >> > > >>
> > > >> > > >> > > >> Not sure about your line of thoughts :-)
> > > >> > > >> > > >>
> > > >> > > >> > > >> My understanding
> > > >> > > >> > > >>
> > > >> > > >> > > >> * There is a recipe out there how someone can access
> the
> > > >> file
> > > >> > > >> system
> > > >> > > >> > and
> > > >> > > >> > > >> the setup was not bad security-wise - only "?api"
> > built-in
> > > >> was
> > > >> > > >> enabled
> > > >> > > >> > > >> * I think the "?api.class.getResource" and
> > > >> > > >> > > >> "?api.class.getResourceAsStream" can be marked as
> unsafe
> > > >> > method?
> > > >> > > >> > > >> * I also think that ALLOWS_NOTHING_RESOLVER is not the
> > > >> default
> > > >> > > >> > > >> configuration?
> > > >> > > >> > > >> * I actually tried the published code and it reads my
> > > >> > > >> "/etc/passwd" :(
> > > >> > > >> > > >>
> > > >> > > >> > > >> If the assumptions above are correct - can this
> > particular
> > > >> > attack
> > > >> > > >> be
> > > >> > > >> > > >> avoided? If so we should react and improve the
> > > configuration
> > > >> > ...
> > > >> > > >> > > >>
> > > >> > > >> > > >> Thanks in advance,
> > > >> > > >> > > >>
> > > >> > > >> > > >> Siegfried Goeschl
> > > >> > > >> > > >>
> > > >> > > >> > > >>
> > > >> > > >> > > >>> On 24.12.2019, at 11:50, Daniel Dekany <
> > > >> > [email protected]
> > > >> > > >
> > > >> > > >> > > wrote:
> > > >> > > >> > > >>>
> > > >> > > >> > > >>> The blog entry might starts its case with a privilege
> > > >> > escalation
> > > >> > > >> > > >>> independent of FreeMarker, but the question you got
> > > during
> > > >> > your
> > > >> > > >> > > >>> presentation wasn't about that, I think. But more
> > > >> importantly,
> > > >> > > >> some
> > > >> > > >> > > real
> > > >> > > >> > > >>> world applications do allow editing templates for
> users
> > > who
> > > >> > > aren't
> > > >> > > >> > > >>> necessarily some kind of superusers. Right now, after
> > > they
> > > >> > > >> realized
> > > >> > > >> > > that
> > > >> > > >> > > >>> the problem exists at all, they will have to figure
> > out a
> > > >> > > solution
> > > >> > > >> > > >>> themselves. We are in a much better position to do
> the
> > > >> same.
> > > >> > > >> > > >>>
> > > >> > > >> > > >>> DOS-ing is certainly less of a concern in general,
> > though
> > > >> > > >> > unintentional
> > > >> > > >> > > >>> DOS-ing (or I guess unintentional) was a problem for
> > > >> > > >> > > >>> try.freemarker.apache.org in the past. My point
> there
> > is
> > > >> just
> > > >> > > >> that
> > > >> > > >> > if
> > > >> > > >> > > >>> really everyone from the Internet can edit templates,
> > > then
> > > >> it
> > > >> > > will
> > > >> > > >> > be a
> > > >> > > >> > > >>> problem, I guess for any practical template language.
> > > >> > > >> > > >>>
> > > >> > > >> > > >>>
> > > >> > > >> > > >>> On Mon, Dec 23, 2019 at 11:55 PM Siegfried Goeschl <
> > > >> > > >> > > >>> [email protected]> wrote:
> > > >> > > >> > > >>>
> > > >> > > >> > > >>>> Hi Daniel,
> > > >> > > >> > > >>>>
> > > >> > > >> > > >>>> I guess I need to re-read the FreeMarker
> documentation
> > > and
> > > >> > > >> ticket -
> > > >> > > >> > > >> having
> > > >> > > >> > > >>>> said that
> > > >> > > >> > > >>>>
> > > >> > > >> > > >>>> * The problem described in the article was less
> about
> > > >> > arbitrary
> > > >> > > >> > people
> > > >> > > >> > > >> but
> > > >> > > >> > > >>>> someone who hacked through other security issues to
> > > become
> > > >> > > >> > > administrator
> > > >> > > >> > > >>>> with temple editing rights
> > > >> > > >> > > >>>> * The people having that skills usually don't have
> any
> > > >> > interest
> > > >> > > >> in
> > > >> > > >> > > >>>> starting a DOS attack by messing up templates -
> there
> > > are
> > > >> > more
> > > >> > > >> > > valuable
> > > >> > > >> > > >>>> things out there ...
> > > >> > > >> > > >>>> * I think it is pretty much impossible to make
> > > FreeMarker
> > > >> > 100%
> > > >> > > >> > bullet
> > > >> > > >> > > >>>> proof (tons of features, a lot of code, arbitrary
> > > >> libraries
> > > >> > > >> coming
> > > >> > > >> > > from
> > > >> > > >> > > >> the
> > > >> > > >> > > >>>> application) but at least we can check that this
> > attack
> > > >> does
> > > >> > > not
> > > >> > > >> > work
> > > >> > > >> > > >> any
> > > >> > > >> > > >>>> longer
> > > >> > > >> > > >>>> * From my understanding - usually there a couple of
> > > >> security
> > > >> > > >> > > >>>> vulnerabilites leading to complete data breach :-)
> > > >> > > >> > > >>>>
> > > >> > > >> > > >>>> Thanks in advance,
> > > >> > > >> > > >>>>
> > > >> > > >> > > >>>> Siegfried Goeschl
> > > >> > > >> > > >>>>
> > > >> > > >> > > >>>>
> > > >> > > >> > > >>>>> On 23.12.2019, at 22:30, Daniel Dekany <
> > > >> > > [email protected]
> > > >> > > >> >
> > > >> > > >> > > >> wrote:
> > > >> > > >> > > >>>>>
> > > >> > > >> > > >>>>> Hi,
> > > >> > > >> > > >>>>>
> > > >> > > >> > > >>>>> In short, allowing untrusted users to edit
> templates
> > is
> > > >> not
> > > >> > > >> > > supported.
> > > >> > > >> > > >>>> But,
> > > >> > > >> > > >>>>> since people do it anyway, 2.3.30 will make an
> effort
> > > to
> > > >> > allow
> > > >> > > >> > doing
> > > >> > > >> > > >> that
> > > >> > > >> > > >>>>> with taking far less risk than what people take
> now.
> > > The
> > > >> > > >> > > >>>> MemberAccessPolicy
> > > >> > > >> > > >>>>> feature committed in recent days is the start of
> > that.
> > > >> > > Actually,
> > > >> > > >> > you
> > > >> > > >> > > >>>> could
> > > >> > > >> > > >>>>> always just use SimpleObjectWrapper (as the FAQ
> > > states),
> > > >> but
> > > >> > > >> > clearly
> > > >> > > >> > > >>>> that's
> > > >> > > >> > > >>>>> too limiting for what many (most?) people use
> > > FreeMarker
> > > >> > for.
> > > >> > > >> But
> > > >> > > >> > > >>>> anyway, I
> > > >> > > >> > > >>>>> don't believe that a template engine with the
> > > complexity
> > > >> of
> > > >> > > >> > > FreeMarker
> > > >> > > >> > > >>>> will
> > > >> > > >> > > >>>>> be ever a good fit for applications where random
> > people
> > > >> can
> > > >> > > edit
> > > >> > > >> > > >>>> templates.
> > > >> > > >> > > >>>>> If users are accountable in real life for what they
> > > did,
> > > >> > like
> > > >> > > >> they
> > > >> > > >> > > are
> > > >> > > >> > > >>>>> employees at the client, then probably it will be
> > good
> > > >> > enough,
> > > >> > > >> but
> > > >> > > >> > > not
> > > >> > > >> > > >>>> for
> > > >> > > >> > > >>>>> use cases where anyone can edit templates. If
> nothing
> > > >> else,
> > > >> > > you
> > > >> > > >> > will
> > > >> > > >> > > be
> > > >> > > >> > > >>>> too
> > > >> > > >> > > >>>>> easily DOS-able then.
> > > >> > > >> > > >>>>>
> > > >> > > >> > > >>>>> As of the blog entry, see this:
> > > >> > > >> > > >>>>>
> https://issues.apache.org/jira/browse/FREEMARKER-124
> > > >> > > >> > > >>>>> Here I would add that it's likely that the calls
> used
> > > in
> > > >> the
> > > >> > > >> blog
> > > >> > > >> > > entry
> > > >> > > >> > > >>>>> won't work anymore in 2.3.30. I'm a bit uneasy
> about
> > > >> that,
> > > >> > as
> > > >> > > >> it's
> > > >> > > >> > a
> > > >> > > >> > > >>>>> backward compatibility risk (it won't be just
> > blocking
> > > >> that
> > > >> > > >> single
> > > >> > > >> > > >>>> method),
> > > >> > > >> > > >>>>> while it doesn't provide real security. You need a
> > > >> whitelist
> > > >> > > of
> > > >> > > >> > > what's
> > > >> > > >> > > >>>>> allowed for that (as opposed to a blacklist), and
> > > that's
> > > >> > > >> possible
> > > >> > > >> > to
> > > >> > > >> > > do
> > > >> > > >> > > >>>>> with MemberAccessPolicy, but I will also provide an
> > > >> > > >> implementation
> > > >> > > >> > to
> > > >> > > >> > > >>>> help
> > > >> > > >> > > >>>>> doing that.
> > > >> > > >> > > >>>>>
> > > >> > > >> > > >>>>> Also, in the FAQ:
> > > >> > > >> > > >>>>>
> > > >> > > >> > > >>>>
> > > >> > > >> > > >>
> > > >> > > >> > >
> > > >> > > >> >
> > > >> > > >>
> > > >> > >
> > > >> >
> > > >>
> > >
> >
> https://freemarker.apache.org/docs/app_faq.html#faq_template_uploading_security
> > > >> > > >> > > >>>>>
> > > >> > > >> > > >>>>>
> > > >> > > >> > > >>>>> On Mon, Dec 23, 2019 at 7:25 PM Siegfried Goeschl <
> > > >> > > >> > > >>>>> [email protected]> wrote:
> > > >> > > >> > > >>>>>
> > > >> > > >> > > >>>>>> Hi folks,
> > > >> > > >> > > >>>>>>
> > > >> > > >> > > >>>>>> During my last presentation I was asked about how
> > > secure
> > > >> > > Apache
> > > >> > > >> > > >>>> Freemarker
> > > >> > > >> > > >>>>>> is in the context of user editing their templates
> -
> > > >> well,
> > > >> > > hard
> > > >> > > >> to
> > > >> > > >> > > say
> > > >> > > >> > > >>>>>> without knowing the application.
> > > >> > > >> > > >>>>>>
> > > >> > > >> > > >>>>>> But I came across an interesting article (see
> > > >> > > >> > > >>>>>>
> > > >> > > >>
> > https://ackcent.com/blog/in-depth-freemarker-template-injection/
> > > )
> > > >> > > >> > > >> where
> > > >> > > >> > > >>>>>> the authors successfully hacked a CMS based on
> > Apache
> > > >> > > >> FreeMarker
> > > >> > > >> > > >>>>>>
> > > >> > > >> > > >>>>>> * As far as I know the UNRESTRICTED_RESOLVER is
> the
> > > >> > default?
> > > >> > > >> Maybe
> > > >> > > >> > > >>>>>> ALLOWS_NOTHING_RESOLVER would be a better default?
> > > >> > > >> > > >>>>>> * Enabling "?api" needs to be enabled by
> developers
> > > >> which
> > > >> > is
> > > >> > > >> fine
> > > >> > > >> > > >>>>>> * Update the "unsafeMethods.properties" according
> to
> > > the
> > > >> > > >> article?
> > > >> > > >> > > For
> > > >> > > >> > > >>>> the
> > > >> > > >> > > >>>>>> records "java.lang.Thread.suspend()" is duplicated
> > > >> anyway
> > > >> > > >> > > >>>>>>
> > > >> > > >> > > >>>>>> Thanks in advance,
> > > >> > > >> > > >>>>>>
> > > >> > > >> > > >>>>>> Siegfried Goeschl
> > > >> > > >> > > >>>>>>
> > > >> > > >> > > >>>>>>
> > > >> > > >> > > >>>>>
> > > >> > > >> > > >>>>> --
> > > >> > > >> > > >>>>> Best regards,
> > > >> > > >> > > >>>>> Daniel Dekany
> > > >> > > >> > > >>>>
> > > >> > > >> > > >>>>
> > > >> > > >> > > >>>
> > > >> > > >> > > >>> --
> > > >> > > >> > > >>> Best regards,
> > > >> > > >> > > >>> Daniel Dekany
> > > >> > > >> > > >>
> > > >> > > >> > > >>
> > > >> > > >> > > >
> > > >> > > >> > > > --
> > > >> > > >> > > > Best regards,
> > > >> > > >> > > > Daniel Dekany
> > > >> > > >> > >
> > > >> > > >> > >
> > > >> > > >> >
> > > >> > > >> > --
> > > >> > > >> > Best regards,
> > > >> > > >> > Daniel Dekany
> > > >> > > >> >
> > > >> > > >>
> > > >> > > >> --
> > > >> > > >> Synesty GmbH
> > > >> > > >> Moritz-von-Rohr-Str. 1a
> > > >> > > >> 07745 Jena
> > > >> > > >> Tel.: +49 3641
> > > >> > > >> 5596493Internet: https://synesty.com <https://synesty.com>
> > > >> > > >> Informationen
> > > >> > > >> zum Datenschutz: https://synesty.com/datenschutz
> > > >> > > >> <https://synesty.com/datenschutz>
> > > >> > > >>
> > > >> > > >> Geschäftsführer: Christoph Rüger
> > > >> > > >>
> > > >> > > >> Unternehmenssitz: Jena
> > > >> > > >> Handelsregister B beim Amtsgericht: Jena
> > > >> > > >>
> > > >> > > >> Handelsregister-Nummer: HRB 508766
> > > >> > > >> Ust-IdNr.: DE287564982
> > > >> > > >>
> > > >> > > >
> > > >> > > >
> > > >> > > > --
> > > >> > > > Best regards,
> > > >> > > > Daniel Dekany
> > > >> > > >
> > > >> > >
> > > >> > >
> > > >> > > --
> > > >> > > Best regards,
> > > >> > > Daniel Dekany
> > > >> > >
> > > >> >
> > > >> > --
> > > >> > Synesty GmbH
> > > >> > Moritz-von-Rohr-Str. 1a
> > > >> > 07745 Jena
> > > >> > Tel.: +49 3641
> > > >> > 5596493Internet: https://synesty.com <https://synesty.com>
> > > >> > Informationen
> > > >> > zum Datenschutz: https://synesty.com/datenschutz
> > > >> > <https://synesty.com/datenschutz>
> > > >> >
> > > >> > Geschäftsführer: Christoph Rüger
> > > >> >
> > > >> > Unternehmenssitz: Jena
> > > >> > Handelsregister B beim Amtsgericht: Jena
> > > >> >
> > > >> > Handelsregister-Nummer: HRB 508766
> > > >> > Ust-IdNr.: DE287564982
> > > >> >
> > > >>
> > > >>
> > > >> --
> > > >> Best regards,
> > > >> Daniel Dekany
> > > >>
> > > >
> > > >
> > > > --
> > > > Christoph Rüger, Geschäftsführer
> > > > Synesty <https://synesty.com/> - Anbinden und Automatisieren ohne
> > > > Programmieren
> > > >
> > >
> > >
> > > --
> > > Christoph Rüger, Geschäftsführer
> > > Synesty <https://synesty.com/> - Anbinden und Automatisieren ohne
> > > Programmieren
> > >
> > > --
> > > Synesty GmbH
> > > Moritz-von-Rohr-Str. 1a
> > > 07745 Jena
> > > Tel.: +49 3641
> > > 5596493Internet: https://synesty.com <https://synesty.com>
> > > Informationen
> > > zum Datenschutz: https://synesty.com/datenschutz
> > > <https://synesty.com/datenschutz>
> > >
> > > Geschäftsführer: Christoph Rüger
> > >
> > > Unternehmenssitz: Jena
> > > Handelsregister B beim Amtsgericht: Jena
> > >
> > > Handelsregister-Nummer: HRB 508766
> > > Ust-IdNr.: DE287564982
> > >
> >
> >
> > --
> > Best regards,
> > Daniel Dekany
> >
>
>
> --
> Christoph Rüger, Geschäftsführer
> Synesty <https://synesty.com/> - Anbinden und Automatisieren ohne
> Programmieren
>
> --
> Synesty GmbH
> Moritz-von-Rohr-Str. 1a
> 07745 Jena
> Tel.: +49 3641
> 5596493Internet: https://synesty.com <https://synesty.com>
> Informationen
> zum Datenschutz: https://synesty.com/datenschutz
> <https://synesty.com/datenschutz>
>
> Geschäftsführer: Christoph Rüger
>
> Unternehmenssitz: Jena
> Handelsregister B beim Amtsgericht: Jena
>
> Handelsregister-Nummer: HRB 508766
> Ust-IdNr.: DE287564982
>


-- 
Best regards,
Daniel Dekany

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