as solution, i suggest that by default, port 8877 should be bound to localhost instead of 0.0.0.0. if there is a command line option to make it so, I do not see it in the documentation.
if you suggest a solution using a campus firewall, problem becomes “anybody on the local network can see my files” (also bad). if you suggest solution using firewall rules on my machine, this is functionally equivalent to my solution, but requires more work and root access.
(as alternative solution, please release a version of ROOT that works on macos 14, all I want to do is to look at a couple of plots in a root file)
I am using ubuntu 22 pre-build binary kit for root 6.28.06.
The defective documentation that causes this problem is here:
Issue appears only when your HTTP ports are accessible from outside.
It is not a normal case for desktop machines.
For working on public hosts like lxplus.cern.ch I recommend to use rootssh - which is shortly described under the same link. It is secure while uses unix sockets - which are protected for reading and writing only by the user itself.
In principle, one can switch to unix sockets also in default case. Probably this can be done in next ROOT version. Of course, it only will work on Linux and MacOS.
at Fermilab, a node running an application listening to an external port would be taken off the [internal] network quite promptly.
a) the security hole needs an immediate fix - you may seek an advice from the CERN compsec
b) the suggestion by @dd1 to bind by default the port to localhost makes a lot of sense, and the users need an option to redefine that
in the midas data acquisition system, our default is to bind mhttpd port 80 to localhost, and we instruct users to setup apache password protected https proxy for outside access. internal midas ports also bind to localhost by default. no external ports open by default.
if midas frontend needs to run on another computer, midas provides an access control whitelist and tell users to setup firewall rules.
all this was implemented specifially to run on the CERN network (the ALPHA anti-H experiment) because we had problems with hostile port probing and tcp attack injections (this is inside CERN, behind lxplus).
(if I ever figure out where --web is handled, and I cannot find any documentation on this command line option so far, I guess I can submit a patch to switch it to localhost or to enable the “?localhost” option in root httpd).
can you say more about this? if I am at an internet cafe connected to local wifi, everybody else on the same network can connect to my machine. by default, ubuntu 22.04 has no firewall rules and everybody in the cafe can access my root session, see my files. do try this at home!
macos has a restrictive firewall by default, but if user clicks “yes” on “allow root.exe to accept internet connections?” popup, the problem appears and it is not clear to me how to undo this “yes” to make root secure again. (you cannot try this at home, root is broken on macos 14).
@jonas: Dear Ionas, understanding the gravity of the issue, do yo still want @dd1 to go through the bureaucracy of reporting the issue on github as well? - BTW, he just did what is recommended the ROOT7 web page … For completeness, I could also report this issue to CS.
@dd1 : the slice is thin would it possible in the near future to ask you question(s) about MIDAS ?
at a closer look, it seems that everything needed is already implemented in gui/webdisplay/src/RWebWindowsManager.cxx, and binding the ports to localhost is just a matter of changing the defaults:
/// One also can bind HTTP server socket to loopback address,
/// In that case only connection from localhost will be available:
/// WebGui.HttpLoopback: yes
/// Or one could specify hostname which should be used for binding of server socket
/// WebGui.HttpBind: hostname | ipaddress
/// To use secured protocol, following parameter should be specified
/// WebGui.UseHttps: yes
/// WebGui.ServerCert: sertificate_filename.pem
/// Alternatively, one can specify unix socket to handle requests:
yep - that works - thanks a lot!
One more question: how would a user control the URL of the created canvas page ?
in the example below the generated URL ended up being http_://localhost:9791/win1/?key=949902 (the underscore after “http” is not a typo, but a way to fool the forum software)
how would a remote client know about the “key=949902” part ?
root  TH1F* h2 = new TH1F("h2","h2",100,0,100)
(TH1F *) 0x3237a30
root  h2->Draw()
!!! ATTENTION !!!
ROOT comes with a web-based canvas, which is now being started.
Revert to the legacy canvas by setting "Canvas.Name: TRootCanvas" in rootrc file or
by starting "root --web=off".
Find more info on https://root.cern/for_developers/root7/#twebcanvas
Info in <THttpEngine::Create>: Starting HTTP server on port 127.0.0.1:9791
thank you for the quick solution. please add it to the documentation web page (URL in the OP). please consider posting this information to the ROOT announcements list. all users of ROOT 6.28 must know about this problem. I assume it will be fixed in the next 6.28 point release? or we have to wait for 6.30?
Now that a release with a patch for the bug is provided, would it be prudent that somebody gets in touch with any known package maintainers and lets them know about the urgency, to hopefully minimise any exploitation time where we can. Some packages will have more CI than others and might pick up on the changes automatically, but best to not rely on this as much as possible.