How To Enable IFrame Support on Heroku with Ruby on Rails and Sinatra
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Web application frameworks are made to help developers build web applications. Some of them also help you with securing the web application. In fact one framework is not more secure than another: If you use it correctly, you will be able to build secure apps with many frameworks.
Ruby on Rails has some clever helper methods, for example against SQL injection, so that this is hardly a problem. It's nice to see that all of the Rails applications I audited had a good level of security. In general there is no such thing as plug-n-play security. Security depends on the people using the framework, and set x-frame-options in rails on the development method.
And it depends on all layers of a web application environment: The back-end storage, the web server and the web application itself and possibly other layers or applications. This is because web applications are relatively easy to attack, as they are simple to understand and manipulate, even by the lay person. The threats against web applications include user account hijacking, bypass of access control, reading or modifying sensitive data, or presenting fraudulent content.
Or an attacker might be able to install a Trojan horse program or unsolicited e-mail sending software, aim at financial enrichment or cause brand name damage by modifying company resources. In order to prevent attacks, minimize their impact and remove points of attack, first of all, you have to fully understand the attack methods in order to find the correct countermeasures. That is what this guide aims at. In order to develop secure web applications you have to keep up to date on all layers and know your enemies.
To keep up to date subscribe to security mailing lists, read security blogs and make updating and security checks set x-frame-options in rails habit check the Additional Resources chapter. I do it manually because that's how you find the nasty logical security problems. A good place to start looking at security is with sessions, which can be vulnerable to particular attacks.
Most applications need to keep track of certain state of a particular user. This could be the contents set x-frame-options in rails a shopping basket or the user id of the currently logged in user. Without the idea of sessions, the user would have to identify, and probably authenticate, on every request. Rails will create a new session automatically if a new user accesses the application.
It will load an existing session if the user has already set x-frame-options in rails the application. A session usually consists of a hash of values and a session id, usually a character string, to identify the hash. Every cookie sent to the client's browser includes the session id. And the other way round: In Rails you can save and retrieve values using the session method:.
A session id consists of set x-frame-options in rails hash value of a random string. The random string is the current time, a random number between 0 and 1, the process id number of the Ruby interpreter also basically a random number and a constant string. Currently it is not feasible to brute-force Rails' session ids. To date MD5 is uncompromised, but there have been collisions, so it is theoretically possible set x-frame-options in rails create another input text with the same hash value.
But this has had no security impact to date. Set x-frame-options in rails a user's session id lets an attacker use the web application in the victim's name. Many web applications have an authentication system: From now on, the session is valid. On every request the application will load the user, identified by the user id in the session, without the set x-frame-options in rails for new authentication.
The session id in the cookie identifies the session. Hence, the cookie serves as temporary authentication for the web application. Anyone who seizes a cookie from someone else, may use the web application as this user - with possibly severe consequences.
Here are some ways to hijack a session, and their countermeasures:. Sniff the cookie in an insecure network. A wireless LAN can be an example of such a network.
In an unencrypted wireless LAN it is especially easy to listen to the traffic of all connected clients. This is one more reason not to work from a coffee shop. For the web application builder this means set x-frame-options in rails provide a secure connection over SSL.
Most people don't clear out the cookies after working at a public terminal. So if the last user didn't log out of a web application, you would be able to use it as this user. Provide set x-frame-options in rails user with a log-out button in the web application, and make it prominent. Many cross-site scripting XSS exploits aim at obtaining the user's cookie. You'll read more about XSS later.
Instead of stealing a cookie unknown to the attacker, they fix a user's session identifier in the cookie known to them. Read more about this so-called session fixation later.
The main objective of most attackers is to make money. Do not store large objects in a session. Instead you should store them in the database and save their set x-frame-options in rails in the session.
This will eliminate synchronization headaches set x-frame-options in rails it won't fill up your session storage space depending on what session storage you chose, see below. This will also be a good idea, if you modify the structure of an object and old versions of it are still in some user's cookies.
With server-side session storages you can clear out the sessions, but with client-side storages, this is hard to mitigate. Critical data should not be stored in session. If the user clears their set x-frame-options in rails or closes the browser, they set x-frame-options in rails be lost.
And with a client-side session storage, the user can read the data. Rails provides several storage mechanisms for the session hashes. The most important is ActionDispatch:: Rails 2 introduced a new default session storage, CookieStore. CookieStore saves the session hash directly in a cookie on the client-side.
The server retrieves the session hash from the cookie and eliminates the need for set x-frame-options in rails session id. That will greatly increase the speed of the application, but it is a controversial storage option and you have to think about the security implications of it:. Cookies imply a strict size limit of 4kB. This set x-frame-options in rails fine as you should not store large amounts of data in a session anyway, as described before. Storing the current user's database id in a session is usually ok.
The client can see everything you store in a session, because it is set x-frame-options in rails in clear-text actually Baseencoded, so not encrypted. So, of course, you don't want to store any secrets here.
To prevent session hash tampering, a digest is calculated from the session with a server-side secret and inserted into the end of the cookie. That means the security of this storage depends on this secret and on the digest algorithm, which defaults to SHA1, for compatibility. So don't use a trivial secret, i. Read the upgrade documentation for more information. If set x-frame-options in rails have received an application where the secret was exposed e.
Another sort of attack you have to be aware of when using CookieStore is the replay attack. Including a nonce a random value in the session solves replay attacks.
A nonce is valid only once, and the server has to keep track of all the valid nonces. It gets even more complicated if you have several application servers mongrels. Storing nonces in a database table would defeat the entire purpose of CookieStore avoiding accessing the database. The best solution against it is not to store this kind of data in a session, but in the database. Apart from stealing a user's session id, the attacker may fix a session id known to them. This is called session fixation.
This attack focuses on fixing a user's session id set x-frame-options in rails to the attacker, and forcing the user's browser into using this id. It is therefore not necessary for the attacker to steal the session id afterwards. Here is how this attack works:. The most effective countermeasure is to issue a new session identifier and declare the old one invalid after a successful login. That way, an attacker cannot use the fixed session identifier. This is set x-frame-options in rails good countermeasure against session hijacking, as well.
Here is how to create a new session in Rails:. Note that this removes any value from the session, you have to transfer them to the new session. Another countermeasure is to save user-specific properties in the sessionverify them every time a request comes in, and deny access, if the information does not match. Such properties could be the remote IP address or the user agent the web browser namethough the latter is less user-specific.
When saving the IP address, you have to bear in mind that there are Internet service providers or large organizations that put their users behind proxies. These might change over the course of a sessionso these users will not be able to use your application, or only in a limited way. Sessions that never expire extend the time-frame for attacks such as cross-site request forgery CSRFsession hijacking and session fixation.