#1269 new
Peter Hilton

CAPTCHA example contans security vulnerability

Reported by Peter Hilton | November 20th, 2011 @ 02:23 PM

Reported by Daniel Dekany | August 23rd, 2011 @ 01:31 PM (moved from www.playframework.org project)

Here: http://www.playframework.org/documentation/1.2.1/guide5
You have this:

public static void captcha(String id) {
    Images.Captcha captcha = Images.captcha();
    String code = captcha.getText("#E4EAFD");
    Cache.set(id, code, "10mn");

Since the ID comes from an URL, the visitor can overwrite whatever cached value with whose name is known (not random).

I think there's yet another vulnerability in the example code (didn't double check it, but I'm certainly right). If someone solves a CAPTCHA, they can re-use the solution to solve other CAPTCHA-s by sending the same randomID as earlier. So a human solves the CAPTCHA, then using the randomID and the solution can flood the site with a program. You should delete the cache entry after checking to fix this.
I'm sure many users blindly copy-paste from the documentation, so it's probably important to fix these.

Comments and changes to this ticket

Please Sign in or create a free account to add a new ticket.

With your very own profile, you can contribute to projects, track your activity, watch tickets, receive and update tickets through your email and much more.

New-ticket Create new ticket

Create your profile

Help contribute to this project by taking a few moments to create your personal profile. Create your profile »

<h2>Play framework</h2>

Play makes it easier to build Web applications with Java. It is a clean alternative to bloated Enterprise Java stacks. It focuses on developer productivity and targets RESTful architectures. Learn more on the <a href="http://www.playframework.org">http://www.playframework.org</a> website.<br><br>

<h2>Source code is hosted on github</h2>Check out our repository at <a href="http://github.com/playframework/play">http://github.com/playframework/play</a><br><br>

<h2>Contributing, creating a patch</h2> Please read the <a href="http://play.lighthouseapp.com/projects/57987/contributor-guide">contributor guide</a><br><br>

<h2>Reporting Security Vulnerabilities</h2> Since all bug reports are public, please report any security vulnerability directly to <em>guillaume dot bort at gmail dot com</em>.<br><br>

<h2>Creating a bug report</h2> Bug reports are incredibly helpful, so take time to report bugs and request features in our ticket tracker. We’re always grateful for patches to Play’s code. Indeed, bug reports with attached patches will get fixed far quickly than those without any.<br><br>

Please include as much relevant information as possible including the exact framework version you're using and a code snippet that reproduces the problem.<br><br>

Don't have too much expectations. Unless the bug is really a serious "everything is broken" thing, you're creating a ticket to start a discussion. Having a patch (or a branch on Github we can pull from) is better, but then again we'll only pull high quality branches that make sense to be in the core of Play.