A cookie, also known as an HTTP cookie, web cookie, or browser cookie, is used for an origin website to send state information to a user's browser and for the browser to return the state information to the origin site. The state information can be used for authentication, identification of a user ...

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5
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3answers
468 views

Is randomizing cookie names a good idea?

What security benefits would randomizing cookie names on a website offer? What are some of the challenges it would create?
5
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3answers
658 views

Are there security (esp. privacy) benefits to deleting cookies?

As the title says, I'm wondering if there are any security/privacy benefits to managing cookies - that is, managing by deleting cookies you don't want or need. I deleted all my cookies about a week ...
5
votes
4answers
620 views

XSS for stealing cookies … not anymore?

The other day I found a XSS vulnerability in a website that a friend told me to Pentest. It was a page from a school that he's managing, so the important thing here is the login credentials == ...
5
votes
3answers
1k views

Do I need to expire a session cookie when sessions are handled server-side?

The only data in the cookie is the session ID. There is no expiration timestamp set when creating it, a session is always evaluated server-side to see if it has expired. When logging out, the session ...
5
votes
3answers
293 views

What are the security implications of allowing unlimited size cookies?

Our application firewall blocks requests if it detects a cookie is present with a value greater than 1024 characters in size. Are there any exploits involving large cookies? i.e. How much more ...
5
votes
2answers
391 views

What protects cookies?

What protects cookies from being stolen? After all, they are just text files. A misbehaving browser can give up a lot more information that web masters would like. How do I know that a browser won't ...
5
votes
1answer
889 views

What kind of vulnerability would this exploit?

We're currently having our website pentested, and looking through our logs, a cookie we set (our allowCookies cookie) has had the value set to ...
5
votes
2answers
5k views

Can Cookies Without the Secure Flag be Stolen, even when only accessed via HTTPS?

Is it possible to capture the cookies used by HTTPS site when cookies don't have secure flag set. Suppose the site is https://www.example.com. http://www.example.com does not show up, also ...
5
votes
1answer
464 views

Using javascript, is it possible to iterate through all cookies saved in the user browser and send them to me?

Again, I am new to the programming and security world. I should mention that it is just a theoretical question so I can anticipate this kind of attack. Using javascript, is it possible to iterate ...
5
votes
1answer
751 views

A Secure Cookie Protocol

As title says I'm trying to implement a secure cookie protocol HMAC(username|expiration name|data|session key, sk) It seams that session key is not constant during whole application session ...
5
votes
1answer
255 views

What issues might exist with TLS-OBC's emulation of Browser Certificates?

TLS-OBC is an RFC proposal that increases SSL/TLS security by using certificates on both ends of the TLS connection. What's special here is that the client is permitted to dynamically create a local, ...
5
votes
2answers
1k views

anti-replay attack for secure cookies?

In the system that i'm working on, we are having some session cookies on the client side that we need to protect against the replay attack ! So I find the following paper ...
5
votes
2answers
7k views

Best way to securely set a session cookie on another domain

We currently have 2 sites http://www.foo.co.uk and https://secure.foo.com. The www site does not have an SSL certificate and is on a different domain. We have a login button on http://www.foo.co.uk ...
5
votes
1answer
545 views

Secure web user authentication even after server-side database compromise

By now, we should all know to use bcrypt or scrypt to store salted password hashes with a sufficient number of rounds. (See, e.g., https://www.owasp.org/index.php/Password_Storage_Cheat_Sheet) The ...
5
votes
1answer
168 views

What's the risk in putting semantically meaningful data in an HTTP session identifier?

I'm currently looking at performance optimization and am considering a way of speeding up cookie based session handling. There are advantages to having a session identifier in place when there is no ...
4
votes
2answers
2k views

Are PHP Sessions based on cookies or a cookie-IP pair?

I have a PHP website and my question is: If someone manages to steal my users' cookies via an XSS attack, is it enough for him to be identified as the user? Or does his IP also have to be the same as ...
4
votes
2answers
329 views

Why Sniff Session Cookies when UN/PW should also be available?

I've recently been reading on session cookies and how they can be hijacked via man-in-middle attacks. It seems this is mainly possible on an unencrypted connection between a client and a webserver. ...
4
votes
3answers
192 views

Letting users pick up where they left off…without logging in (is this bad form?)

I have a Grails app I'm working on that allows users to fill out a fairly lengthy application form. One of the requirements I've been given is to NOT require users to log in or create any sort of ...
4
votes
6answers
3k views

Is cookie-based XSS exploitable?

Today I've found interesting site that output your cookie value directly to the page, so if I modify the cookie value I can XSS myself. e.g <span id=statistics>Last visit: ...
4
votes
2answers
2k views

Double Submit Cookies vulnerabilities

Is the Double Submit Cookies mechanism vulnerable anything other than XSS and sub-domain attacks? All CSRF protection mechanisms are vulnerable to XSS, so that's nothing new. I'm just wondering if I ...
4
votes
2answers
15k views

XSS cookie stealing without redirecting to another page

I'm practicing in VM following the OWASP guide. I know that is possible to steal the cookie by redirecting to "False" page etc. but I would like to steal the cookie without redirecting on another ...
4
votes
4answers
3k views

Is it possible to force a browser to use http in an ssl enabled (https) website?

I was doing a security research on storing the session id in local storage instead of storing it in cookies. I understand that it is not possible to tag the values in local storage as HttpOnly and so ...
4
votes
3answers
1k views

Session fixation attack

Given the following conditions, Session ID does not change upon login Session ID travels in form of HTTP cookie There is no cross site scripting/redirection vulnerability on the login page is it ...
4
votes
2answers
65 views

Securely store session data in cookies

I'm trying to create a stateless application server architecture and I would like to store session data in cookies. All pages using the session would be served over HTTPS. I was planning on using ...
4
votes
1answer
50 views

Ideal time for cookies to expire?

I get that websites that contain confidential personal information (e.g. banking system) have short sessions and expiration time for cookies for obviously reason. But what are the causes for sites, ...
4
votes
2answers
251 views

Does the ability for a user to choose the value of a session id cookie constitute a security flaw?

In the context of a web application, a user connects to this application and a session id cookie is set to authenticate the user for next requests. As the cookie is actually present before submitting ...
4
votes
2answers
192 views

Is HTTPS redirecting to HTTP a vulnerability?

Let's say a user is authenticated, and the entire account authentication process happened under secure HTTPS. Upon successful login, the user is redirected back to the homepage. However, the homepage ...
4
votes
1answer
162 views

Resources/materials for implementing secure web services?

I'm implementing a REST-style (note: it needs to be more pragmatic than canonical) web API and I would like to secure it. The language I'm using is rather fresh and doesn't have a lot of high quality ...
4
votes
3answers
898 views

Deciding whether user has left the site without logging out or has simply left the site open for notifications without actually doing any work?

I am developing my site using server side sessions using redis as backend for saving the session. Now the issue which is bothering me is of user leaving the website without logging out. I mean user ...
4
votes
1answer
59 views

Storing personal information in cookies

I'm trying to do a simple display integration between two websites. One on: domain.com and another on: subdomain.domain.com All I want to do is show a "Hello John, Return to Client Area" ...
4
votes
1answer
117 views

How to find out whether an ISP adds a perma-cookie to my requests?

I am interested in finding out whether my (or any) current ISP (Internet Service Provider) uses a technology known as "perma-cookie" oder "sticky cookie" when I am browsing the internet. This ...
4
votes
1answer
1k views

How to detect cookie stuffing attacks?

So the question is how to detect cookie stuffing attacks and how to protect against them? In case of image-based cookie stuffing I can detect that related resources are not loaded and therefore ...
4
votes
1answer
848 views

Does returning `Access-Control-Allow-Origin: *` weaken the security of JSON GET responses?

The W3C CORS recommendation states: Certain types of resources should not attempt to specify particular authorized origins, but instead either deny or allow all origins. ... 3. A GET ...
4
votes
2answers
3k views

Session Authentication vs Token Authentication

I am trying to get a handle on some terms and mechanisms and find out how they relate to each other or how they overlap. Authenticating a theoretical web application and mobile application is the ...
4
votes
1answer
281 views

XSS via PDF when Content-Disposition: Inline?

There are kind of two questions here: Is it possible to have XSS in a PDF file when the Content-Disposition: is "inline"? If it is possible, does the pdf get access to the cookies for that domain ...
3
votes
2answers
843 views

Is it possible to steal a non secure Cookie when the Web Server (IIS) only allows Https?

Is it possible to steal a non secure Cookie (Secure Flag is false) when the Web Server (IIS) only allows Https?
3
votes
2answers
2k views

How can Bank of America tell that I'm logging in on a computer I haven't used with them before?

When you sign into Bank of America for the first time on a computer that you haven't used with them before, they detect this and force you to answer one of your security questions. I think I've seen ...
3
votes
5answers
640 views

Does setting the cookie-path protect me from XSS from another context?

Lets say I am using a reverse proxy with URL rewriting that provides access to 2 different applications http://www.example.com/app1/ and http://www.example.com/app2/. I don't want those ...
3
votes
1answer
2k views

Are passwords stored in the cookie? encrypted?

Whenever I connect to security.stack.exchange, I am automatically logged in. I haven't allowed the browser to store my password. When I delete all cookies stored by the security.stack.exchange, I have ...
3
votes
2answers
780 views

Reusing the same session-ID necessarily bad?

The question is related to session-ID management in a particular php-based web-app. The web-app uses the same session-ID for each session for a fixed user. So, after logging-out of the application, ...
3
votes
2answers
553 views

Security concerns about my webapp

I read though OWASP very carefully, but I am not sure about some parts of my website. I am using jbcrypt on my website. It stores the salt in the hash itself something like this hash+salt. I read ...
3
votes
4answers
3k views

Can a session be hijacked if the user is redirected from HTTPS to HTTP after login?

I am developing a web app, which makes HTTP calls as long as the user is not logged in. Once the user clicks the login button, he is sent to a "login page" that is HTTPS. The login makes an Ajax call ...
3
votes
3answers
12k views

What typically is the expiration date of a session cookie?

I need to create a session cookie using JavaScript (for more info see question). I'm wondering what should the expiry date be? I'm guessing it's the browsing session, so if I don't set an expiration ...
3
votes
2answers
1k views

Is my current method of handling session cookies insecure?

I'm writing a multi-tenant application where accounts are scoped by subdomains. This adds considerable complexity and I'm starting to worry about security. Each user can have several accounts. For ...
3
votes
4answers
226 views

Improving the privacy of a casual Web user

I am interested in improving the privacy available to me as a casual internet user with a default browser. I think that Tor is too slow and that the "Privacy Mode" in browsers isn't really practical. ...
3
votes
5answers
562 views

Is it possible to see if a script on a website steals session cookies?

I'm looking as some web analytics solutions, I know it sounds paranoid. but cookie-based web analytics need for you to paste their JavaScript code on your web-site. I don't like the idea too much of ...
3
votes
2answers
3k views

Why are CSRF tokens necessary?

It seems that the entire problem could be solved very elegantly by simply adding a new flag to the HTTP cookie specification. Similarly to how cookies flagged Secure will only be submitted by the ...
3
votes
2answers
474 views

Web security - use of cookie in https

I am taking a web security class and was told by the instructor that most of the websites today use https for authentication and then use a cookie (authentication token) in plain text to keep track of ...
3
votes
2answers
374 views

Computer-level logging by financial institutions

I am looking for the best approach to recognizing a specific computer and saving that computer as a "safe" login machine. My intuition points me to using cookies, but what value do I store in there to ...
3
votes
1answer
718 views

HeartBleed - how do I invalidate all session cookies?

As part of the Heartbleed event, I have upgraded OpenSSL, reissued and replaced certificates and revoked the old ones and changed passwords however, I am also seeing advice to invalidate all session ...