Simon Willison’s Weblog

Items tagged csrf in 2008

Filters: Year: 2008 × csrf ×

When visiting any Web page, the site owner is easily able to ascertain what websites you’ve visited (CSS color hacks) or places you’re logged-in (JavaScript errors / IMG loading behavior). They can also automatically exploit your online bank, social network, and webmail accounts (XSS). Additionally, the browser could be instructed to hack devices on the intranet, including DSL routers and printers. And, if that’s not enough, they could turn you into a felon by forcing requests to illegal content or hack other sites (CSRF).

Jeremiah Grossman # 3rd November 2008, 12:43 pm

Web Security Horror Stories: The Director’s Cut. Slides from the talk on web application security I gave this morning at <head>, the worldwide online conference. I just about managed to resist the temptation to present in my boxers. Topics include XSS, CSRF, Login CSRF and Clickjacking. # 26th October 2008, 12:15 pm

We’ve found CSRF vulnerabilities in sites that have a huge incentive to do security correctly. If you’re in charge of a website and haven’t specifically protected against CSRF, chances are you’re vulnerable.

Bill Zeller # 29th September 2008, 1:11 pm

Popular Websites Vulnerable to Cross-Site Request Forgery Attacks. Ed Felten and Bill Zeller announce four CSRF holes, in ING Direct, YouTube, MetaFilter and the New York Times. The ING Direct hole allowed transfer of funds out of a user’s bank accounts! The first three were fixed before publication; the New York Times hole still exists (despite being reported a year ago), and allows you to silently steal e-mail addresses by CSRFing the “E-mail this” feature. # 29th September 2008, 1:08 pm

Logout/Login CSRF. Alf Eaton built an example page (this link goes to his description, not the page itself) that uses a login CSRF attack to log you in to Google using an account he has created. Scary. # 24th September 2008, 10:18 pm

csrf_protect.php. A PHP class for applying CSRF protection to existing PHP applications, using output buffering to rewrite any POST forms on a page. Heavily inspired by Django’s CSRF middleware. Tell me if you spot any bugs! # 24th September 2008, 2:52 pm

Robust Defenses for Cross-Site Request Forgery [PDF]. Fascinating report which introduces the “login CSRF” attack, where an attacker uses CSRF to log a user in to a site (e.g. PayPal) using the attacker’s credentials, then waits for them to submit sensitive information or bind the account to their credit card. The paper also includes an in-depth study of potential protection measures, including research that shows that 3-11% of HTTP requests to a popular ad network have had their referer header stripped. Around 0.05%-0.10% of requests have custom HTTP headers such as X-Requested-By stripped. # 24th September 2008, 9:40 am

When Ajax Attacks! Web application security fundamentals. Slides and notes from my talk on web application security at @media Ajax last Tuesday. # 20th September 2008, 4:16 pm

When Ajax Attacks! Web application security fundamentals. Slides and (other people’s) notes from my presentation at @media Ajax on Tuesday. # 17th September 2008, 11:18 pm

Django: Security fix released. The Django admin used to save partially-submitted forms if your session expired, and continue the submission when you logged in. It turns out that’s actually an unblockable CSRF exploit and is hence broken as designed, so it’s now been removed. Thanks Ed Eliot and other GCap colleagues for helping me flesh out the potential attack. # 3rd September 2008, 12:14 am

ratproxy. “A semi-automated, largely passive web application security audit tool”—watches you browse and highlights potential XSS, CSRF and other vulnerabilities in your application. Created by Michal Zalewski at Google. # 3rd July 2008, 2:35 pm

Crossdomain.xml Invites Cross-site Mayhem. A useful reminder that crossdomain.xml files should be treated with extreme caution. Allowing access from * makes it impossible to protect your site against CSRF attacks, and even allowing from a “circle of trust” of domains can be fatal if just one of those domains has an XSS hole. # 15th May 2008, 8:06 am

CSRF presentation at RSA 2008. It terrifies me how few people understand CSRF, years after it was discovered. I’ll say it again: if you’re a web developer and you don’t know what that acronym means, go spend an hour reading about it—because the chances are your applications are vulnerable. # 12th April 2008, 10:52 am

Major Update to Prism (via) Mozilla’s site-specific browser tool can now use separate profiles (and hence separate cookie jars) for each instance, making it an excellent tool for protecting yourself against CSRF vulnerabilities in the web applications you rely on. # 10th March 2008, 2:03 pm