Why isn't giving end-users a repl dangerous?

[mars0i]

A good rule of thumb: One should worry that giving end-users access to a full-fledged eval function can be dangerous, because users can then do anything that the language can do, and cause damage to their own system or to others'.

There are numerous Clojurescript repls embedded in public web pages, so this apparently isn't a problem (or it's a problem that can easily be avoided).

My hypothesis is that browser repls aren't considered problematic because the repl is running in a browser on the user's machine, so that the worst that they can do is cause damage to themselves. Still, one could imagine someone telling an uninformed person to do something that would be bad for their system. (Is it not possible to do file io, for example, from a browser repl?)

I'm going to be working on a small web page in which it would be helfpul to let users define Clojurescript functions that affect output on the page. So I started to worry about whether there are dangers that I need to avoid. It might be simplest to simply give users access to a repl, but I could also process their definitions myself, passing them to eval, for example.

Please feel free to simply point me to a useful discussion of this issue on the web, and we can end this thread early. :-)

[Brandon Adams]

The users already have a javascript repl with the same abilities and permissions as the cljs repl you give them. 

--
Note that posts from new members are moderated - please be patient with your first post.
---
You received this message because you are subscribed to the Google Groups "ClojureScript" group.
To unsubscribe from this group and stop receiving emails from it, send an email to clojurescript+unsubscribe@googlegroups.com.
To post to this group, send email to clojur...@googlegroups.com.
Visit this group at https://groups.google.com/group/clojurescript.

[mars0i]

On Sunday, September 25, 2016 at 12:32:36 AM UTC-5, Brandon Adams wrote:
> The users already have a javascript repl with the same abilities and permissions as the cljs repl you give them.

Oh! Good point. Got it. Thanks.

[Yehonathan Sharvit]

There might me security issues if the website allows users to modify the contents of the page - like Wikipedia or clojuredocs.org.

A malicious user might write cljs code that will do malicious actions that run on the browser of all your visitors

There might me security issues if the website allow users to modify the contents of the page - like Wikipedia or clojuredocs.org.

A malicious user might write cljs code that will do malicious actions that run on the browser of all your visitors...

[mars0i]

I understand. In my application, users will affect the output they see in their browser, but I don't see any way that they could modify what I put on the server, which will always be the same unless I change it. Thanks for clarifying that.

[Yehonathan Sharvit]

By the way, the klipse plugin does something similar. You might want to take a look at
https://github.com/viebel/klipse

--
Note that posts from new members are moderated - please be patient with your first post.
---

You received this message because you are subscribed to a topic in the Google Groups "ClojureScript" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/clojurescript/VczAamZK9xQ/unsubscribe.
To unsubscribe from this group and all its topics, send an email to clojurescrip...@googlegroups.com.