I am creating an Angular 1 SPA. Certain controls are only visible to users with certain permissions. This is based on scope variables set by server api calls.
It occurred to me that if I could access these variables through a browsers dev console, I could change their values.
I tried this for example:
angular.element($0).scope().$parent.myUserInfo.accessType = "admin"
angular.element($0).scope().$apply()
And sure enough, the admin controls popped up on the page even though I was not logged in as an admin. Is there a best practice to stop this or am I going about it completely wrong?
The authentication always have to be made on the server side.
I don't know what you are trying to do, but if the user interacts with some webService/Rest API, etc... the server should disallow such interactions.
If the accessType property of your scope is just a way for you to know which UI you should display to the user, and the authentication/session mechanism is correctly handled by the server, that should not be a problem.
However, you cannot disallow the user to play with the dev console, so you'd better handle the authentication correctly.
I am not sure if there is a way of protecting values in $scope.
But as JavaScript is executed client-side and it is therefore be possible for users to modify said code, I would always verify permissions server-side. Then it wouldn't matter if users enable the admin controls client-side as they have no permission to use the api calls.
Related
In attached image button is disabled by default based on access, however if i delete the property highlighted it gets enabled & user can able to perform actions.
Please do provide solution to restrict it.
Please see image attached related to issue with chrome Developer tool
You can't stop the user from doing that. Its their browser, and it's entirely in their control. Any user can manipulate the page in any way they choose, and run any script they choose from the console, etc etc. If the have the knowledge and inclination, they can do as they please. If they want to change the page to try and make a malicious or incorrect submission of they data, they can.
The mitigation you can (and must) put in place is to check and sanitise all data coming into your server-side API to guard against what is coming from the client being malicious or otherwise inappropriate.
Bear in mind your API just accepts HTTP requests, there's nothing to say a client even needs to use your web app to make requests, they could use a tool like PostMan or any other HTTP client to attack it. They can bypass the browser completely. So you have to apply all permissions, data checking etc on the server first to ensure security. If you then apply it on the browser-based web app, that's nice but you have to regard it as just a usability feature - it can never provide any real security.
well, as all html code in the browser you cannot prevent it from being manipulated, never trust the client and check the access of this action in the backend.
Keep in mind that even if the button is disabled, a developer can rebuild the request of this form and send it without using any user interface.
There is an alternative way that you can do in this kind of situation. You must unbind the event when the button is disabled and bind it again when the button is enabled. It will solve your problem.
Much better sanitize it in server side.
I'm building an admin page for an application and have a state value 'authenticated' that flips from 'false' to 'true' after a successful login (which is authenticated on the server) which then shows the actual admin panel.
Are component state values safe from tampering by the client? Basically, if the client can modify my 'authenticated' state value to 'true', they can skip the login and go straight to the admin panel (which I obviously don't want).
I read that React Dev Tools allows the client to modify values yet everyone says "validate on the server" but I am validating on the server and updating my state accordingly, if the user is approved. If it is not wise to have a state value manage this, what is the right way to conditionally show the admin page after a successful, server-side authenticated login?
I think this is an important question since tampering with state values in a React app can have huge negative consequences on data integrity within an app/database.
TL;DR: Either require an authentication token with every request or require authentication through a session.
Never trust users always. One potentially big issue is if you "hide" admin actions behind the admins page without requiring authentication.
For example, assume the backend server uses a REST API to accept commands. In the admin panel you get links to administrative actions like a button 'Delete Everything' that sends a DELETE request to server.net:8080/api/admin/everything without requiring any authentication. If you're a user, you can find that in the code potentially and then send a DELETE request to that address from anywhere without any repercussions.
We'd never give administrative privileges to anyone who would want to delete everything... Because we'll never untrust someone. Right?
Worse, someone might find the server and fuzz some inputs to it, and oops! They manage to delete everything (or even worse, GET everything stored in the database). This wouldn't be hard to do, especially if the server you use to authenticate is the same server you use to issue commands. History has proven "security through obscurity" to be a very bad paradigm. Every action should be authenticated, even if it seems like the actions will be hard to find.
Generally, providing a JSON web token or some other form of authentication token and having the user send that with every request is a good start at least, especially if it has an expiration date. The token would be provided through a separate request with valid credentials.
Sending a token with every single request obviously isn't ideal. There are a couple of other things to try. For servers using PHP, you can probably trust sessions (though very many people who know more than me would probably disagree). In more modern cases, you could try to use Web Sockets, requiring the token after connection. Then only after authentication with the token do you allow the user to make administrative requests.
That way, even if a user knows the exact command they can send to perform any action, the server won't let them without a current session or token. Unfortunately, unless you're already using Web Sockets or depending on a session, it will likely require a lot of changes. I'd consider this to be critical though.
It is always possible to tamper values in the front-end, there is no way you can rely solely on the front end to ensure security.
Your best approach is to implement some form of authentication and authorization on your backend. In this way, even is some users pretend to be admin, they will be blocked when you do the next request to the server.
Perhaps if you can send more information regarding your problem, we can think of a more specific solution.
In a regular web app, when someone logs into the system they simply save an encrypted cookie that gets send on each request and the backend decrypts the cookie and uses the e.g. user_id/guid to lookup the user.
How do things differ when authenticating with a angular app?
Is there anything else to consider or it is basically the same process?
We use more or less the same mechanism.
Access to the application as a whole requires authentication - that is unless you're logged in, you don't get any of the javascript experience at all. This could make the login / login failure much less wizzy for the user, but in our authentication provider it's fine.
Part of our auth mechanism means the list of roles that the user has is a data object available within the browser. The javascript code uses this to decide which buttons / menus etc. are displayed. I checked with our security guy and he said something like "Well, it's a kind of direct object reference issue, but as long as each action is authorised properly, you're probably ok." So it's possible that a user could hack data values and change what they can see, but because of the next bit, they can't break our data (or see stuff that they shouldn't).
Each service call our javascript makes is authenticated and authorised. That is, the javascript call will fail if the auth token is missing or bad, but also, we internally match the auth token with a user and a set of permissions, and only execute that if the user is authorised to do so. (Note that this is good practice whether you're using Angular or not). Also note that this applies to GETs as well as POSTs - we don't want to give them data they should not see.
It gets much trickier if your API is hosted separately from your Angular site.
I am new to AngularJS and trying to grasp the concept of implementing an access control layer so that some pages/menus will be hidden from certain users.
I usually implement ACL and all routes on the back-end (PHP/MySQL) but this project require me to do everything on the client side only.
We have a remote server that is in charge of authentication and upon successful login, will return an is_admin flag so that I know whether to display the additional info.
Although not likely, since Angular is also the rendering engine and is in charge of all the logic, I am afraid that users will be able to play with browser developer tools and/or other 3rd party tools and gain access to those areas (since all scripts & logic will be visible to them in the browser).
So if I do something like:
if (user.is_admin === true)
{
//display the additional admin data...
}
A user can potentially set user.is_admin = true in the browser tools and gain access.
With server side rendering such as PHP, the user will never be able to even know about these hidden areas. i.e
<?php
if ($user->is_admin === true) {...}//user will never ever see that or be able to modify $user properties
?>
Of course that the server will keep on authenticating every request so this exploit will only allow limited access, but still seems like a non secure way of hiding sections from certain users.
Am I missing something in Angular or is there a better way of doing it so that it's bullet-proof for client side hacks?
The Angular way of hiding sections is with the ng-if/ng-show/ng-hide directives, as in:
<div ng-if="is_admin">...</div>
You can't hide those divs from people who look at the source, or the resources you make available in your app. So don't provide admin data to those views.
My approach was to make an "admin" app in addition to the "standard" app and link between them. This way, the only things exposed are links to the admin site, which are blocked to non-admin users:
<div ng-if="is_admin">Link</div>
All requests to my /admin/* pages return a 401 status code if they are not an admin. The REST resources also return 401 status codes as appropriate.
(Edit: changed above ng-hide to ng-if to suppress those divs in the resulting DOM.)
I'm looking for information on how to implement secure pages using ExtJS 4. By secure pages I mean the user will log into our website using Siteminder (SSO) and so we will have the user's identity. Then we would determine what roles the user would have by making a database/LDAP call and only render those views/components that the user has access to.
Several questions come to mind:
1.) Of course I would expect we would do the authorization check prior to rendering the pages on the server-side, so how do you do this prior to firing Ext.onReady()? I need to have the ExtJS wait for the response from the server?
2.) What is the best way to organize a page's components where the case may be someone could see a particular component and another person cannot?
3.) How do I deliver the resulting page (i.e., the pieces the user has access to) to the client?
TIA!
If you're working from a Java background and are comfortable using Spring, I wrote up an approach using Spring Security here. This will allow you to plug-in any authentication mechanism you want. The main difference is that instead of using an index.html to bootstrap the application, I have a JSP so that the Spring Servlet Filter will fire for authentication. The Ext JS app blocks until the user is authenticated and the user's roles/permissions are provided.
Use a server side technology to pre-process authorization by putting your JS App launch script into a JSP/GSP. What this does is forces server side components to kick off first and then render the HTML/JS/CSS to the client. For full RIA app use index.gsp(or jsp) and the your URL stays "domain/contextroot" .
You can interrogate access privs to content via ajax request to server or alternatively you could set JS variables via again JSP technology that is processed first before the rest of the client response is returned.
< g:javascript>
//global env var definition
var env = "${System.getProperty(Environment.KEY)}";
< /g:javascript>
Both of these are not 100% safe as client side code can be altered. The real security enforcement must be handled on server side when data is submitted for processing.
'3. Easy way would be to hide/show views etc based on 2. above. There are also some experimentation out there with modularizing the client side MVC application by lazy(manually) initializing controllers that may or may not be needed.
Hope this helps.
DB :)
I am currently experimenting with the following solution. Although it will only work for apps with a rather simple set of users, it could be of some help to you.
To begin with, user authentication is done without extjs, using a simple HTML/CSS page. Once the user logs in, its details (user id, role) are saved into the PHP session. And then the page redirects to one of two extjs apps.
One app for normal users (I'll call them clients), these are people who's client side JS does not include any admin functionality. The other app is for admins.
Both apps have their classes inherit from base classes. So we have, for example, base.mainMenu from which both admin.mainMenu and clients.mainMenu inherit. The only difference in the app.js script is the controllers loaded, and per extJS 4 dynamic loading module, only the related views are loaded (ie, seen on the client side). In my case, all pages load dynamically anyway, so my users can only dynamically load pages in their mainmenu.
The admin app blocks certain features using a global JS variable that includes the user's role. So for example, the hiding of an 'edit' button from moderators (an admin group with less rights) is done once the view is loaded (in practice this is actually done by not loading a plugin that allows editing on the view).
To wrap it all up, any call to the server checks whether the session user has rights for the requested operation, so regardless of client side scripts, server operation can only be performed by people with the appropriate rights.
To summarise, you have 3 different strategies that you can mix-and-match:
Loading different apps for different users. If your classes all inherent from base classes, this is easier than maintaining 2 or more completely different apps.
Using a global JS variable to disable/enable certain features for certain users. This is only good if you don't have a problem with the client side loading features that are then disabled (but still seen by debuggers).
Regardless of anything, all server-side calls are checked against session variable.
check out Role-based access control. I use Yii's database-based RBAC, and have a php script that returns the rbac rules in json format when ext starts up
on the client, the best bet is to simply hide or disable functionality that is not allowed.
on the server, you should throw a 403 http error if the user is not allowed to perform a function. handle ajax exceptions in ext and check for 403s.