48 items tagged “csrf”
2024
Datasette 1.0a15. Mainly bug fixes, but a couple of minor new features:
- Datasette now defaults to hiding SQLite "shadow" tables, as seen in extensions such as SQLite FTS and sqlite-vec. Virtual tables that it makes sense to display, such as FTS core tables, are no longer hidden. Thanks, Alex Garcia. (#2296)
- The Datasette homepage is now duplicated at
/-/, using the defaultindex.htmltemplate. This ensures that the information on that page is still accessible even if the Datasette homepage has been customized using a customindex.htmltemplate, for example on sites like datasette.io. (#2393)
Datasette also now serves more user-friendly CSRF pages, an improvement which required me to ship asgi-csrf 0.10.
2021
Exploring the SameSite cookie attribute for preventing CSRF
In reading Yan Zhu’s excellent write-up of the JSON CSRF vulnerability she found in OkCupid one thing puzzled me: I was under the impression that browsers these days default to treating cookies as SameSite=Lax, so I would expect attacks like the one Yan described not to work in modern browsers.
OkCupid had a CSRF vulnerability
(via)
Good write-up of a (now fixed) CSRF vulnerability on OkCupid. Their site worked by POSTing JSON objects to an API. JSON POSTs are usually protected against CSRF because they can only be sent using fetch() or XMLHttpRequest, which are protected by the same-origin policy. Yan Zhu notes that you can use the enctype="text/plain" attribute on a form (introduced in HTML5) and a crafty hidden input element with name='{"foo":"' value='bar"}' to construct JSON in an off-site form, which enabled CSRF attacks.
Datasette 0.58: The annotated release notes
I released Datasette 0.58 last night, with new plugin hooks, Unix domain socket support, a major faceting performance fix and a few other improvements. Here are the annotated release notes.
[... 1,062 words]Weeknotes: sqlite-utils updates, Datasette and asgi-csrf, open-sourcing VIAL
Some work on sqlite-utils, asgi-csrf, a Datasette alpha and we open-sourced VIAL.
2020
Weeknotes: Rocky Beaches, Datasette 0.48, a commit history of my database
This week I helped Natalie launch Rocky Beaches, shipped Datasette 0.48 and several releases of datasette-graphql, upgraded the CSRF protection for datasette-upload-csvs and figured out how to get a commit log of changes to my blog by backing up its database to a GitHub repository.
Weeknotes, I guess
What a week. Hard to work up the enthusiasm to write about what I’ve been working on.
[... 314 words]Weeknotes: datasette-ics, datasette-upload-csvs, datasette-configure-fts, asgi-csrf
I’ve been preparing for the NICAR 2020 Data Journalism conference this week which has lead me into a flurry of activity across a plethora of different projects and plugins.
[... 834 words]2020 Web Milestones (via) A lot of stuff is happening in 2020! Mike Sherov rounds it up—highlights include the release of Chromium Edge (Microsoft’s Chrome-powered browser for Windows 7+), Web Components supported in every major browser, Deno 1.x, SameSite Cookies turned on by default (which should dramatically reduce CSRF exposure) and Python 2 and Flash EOLs.
Come version 80, any cookie without a SameSite attribute will be treated as "Lax" by Chrome. This is really important to understand because put simply, it'll very likely break a bunch of stuff. [...] The fix is easy, all it needs is for everyone responsible for maintaining any system that uses cookies that might be passed from an external origin to understand what's going on. Can't be that hard, right? Hello? Oh...
2018
OWASP Top 10 2007-2017: The Fall of CSRF. I was surprised to learn recently that CSRF didn’t make it into the 2017 OWASP Top 10 security vulnerabilities (after featuring almost every year since the list started). The credited reason is that web frameworks do a good enough job protecting against CSRF by default that it’s no longer a top-ten problem. Defaults really do matter.
2011
CSRF: Flash + 307 redirect = Game Over. Here’s the exploit that Django and Rails both just released fixes for. It’s actually a flaw in the Flash player. Flash isn’t meant to be able to make cross-domain HTTP requests with custom HTTP headers unless the crossdomain.xml file on the other domain allows them to, but it turns out a 307 redirect (like a 302, but allows POST data to be forwarded) confuses the Flash player in to not checking the crossdomain.xml on the host it is being redirect to.
2010
OpenCart CSRF Vulnerability. Avoid OpenCart—it’s vulnerable to CSRF, but the maintainer has no intention of fixing it as “there is no way that I’m responsible for a client being stupid enough to click links in emails”.
Django 1.2 release notes (via) Released today, this is a terrific upgrade. Multiple database connections, model validation, improved CSRF protection, a messages framework, the new smart if template tag and lots, lots more. I’ve been using the 1.2 betas for a major new project over the past few months and it’s been smooth sailing all the way.
What’s new in Django 1.2 alpha 1 (via) Multiple database support, improved CSRF prevention, a messages framework (similar to the Rails “flash” feature), model validation, custom e-mail backends, template caching for much faster handling of the include and extends tags, read only fields in the admin, a better if tag and more. Very exciting release.
2009
Django ponies: Proposals for Django 1.2
I’ve decided to step up my involvement in Django development in the run-up to Django 1.2, so I’m currently going through several years worth of accumulated pony requests figuring out which ones are worth advocating for. I’m also ensuring I have the code to back them up—my innocent AutoEscaping proposal a few years ago resulted in an enormous amount of work by Malcolm and I don’t think he’d appreciate a repeat performance.
[... 1,674 words]Amazon Says Listing Problem Was an Error, Not a Hack (via) “A friend within the company told him that someone working on Amazon’s French site mistagged a number of keyword categories, including the ’Gay and Lesbian’ category, as pornographic, using what’s known internally as the Browse Nodes tool. Soon the mistake affected Amazon sites worldwide.”
How to cause moral outrage from the entire Internet in ten lines of code. Looks legit—the author claims to have sparked this weekend’s #amazonfail moral outrage (where Amazon where accused of removing Gay and Lesbian books from their best seller rankings) by exploiting a CSRF hole in Amazon’s “report as inappropriate” feature to trigger automatic takedowns. EDIT: His claim is disputed elsewhere (see comments)
17-year-old claims responsibility for Twitter worm. It was a text book XSS attack—the URL on the user profile wasn’t properly escaped, allowing an attacker to insert a script element linking out to externally hosted JavaScript which then used Ajax to steal any logged-in user’s anti-CSRF token and use it to self-replicate in to their profile.
CSRF is not a security issue for the Web. A well-designed Web service should be capable of receiving requests directed by any host, by design, with appropriate authentication where needed. If browsers create a security issue because they allow scripts to automatically direct requests with stored security credentials onto third-party sites, without any user intervention/configuration, then the obvious fix is within the browser.
2008
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).
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.
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.
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.
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.
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!
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.
When Ajax Attacks! Web application security fundamentals. Slides and notes from my talk on web application security at @media Ajax last Tuesday.
When Ajax Attacks! Web application security fundamentals. Slides and (other people’s) notes from my presentation at @media Ajax on Tuesday.