Simon Willison’s Weblog

Intercepting Predator Video. Bruce Schneier’s take on the unencrypted Predator UAV story. A fascinating discussion of key management and the non-technical side of cryptography. # 24th December 2009, 9:26 pm

The Dangers of Clickjacking with Facebook. theharmonyguy compiled a list of actions that can be triggered on Facebook by a single click, and hence are vulnerable to clickjacking attacks. The list includes authorising malicious applications, posting links to profiles, sending friend requests and sending messages to other users. Why don’t Facebook include frame busting JavaScript on every page? # 23rd December 2009, 10:20 am

New Facebook clickjacking attack in the wild. I’m not sure why Facebook don’t use frame-busting JavaScript to avoid this kind of thing. The attack is pretty crafty—a Facebook page is positioned with everything obscured bar part of the blue “share this” button, and a fake “Human Test” asks the user to find and click the blue button to continue. # 22nd December 2009, 6:52 pm

Another leak, the worst so far (via) “Arweena, a spokes-elf for Santa Claus, admitted a few hours ago that the database posted at WikiLeaks yesterday is indeed the comprehensive 2009 list of which kids have been naughty, and which were nice.” The first comment is great too. # 22nd December 2009, 10:42 am

Insurgents Hack U.S. Drones. The video feed rather than the control protocol, but still.... “Fixing the security gap would have caused delays, according to current and former military officials. It would have added to the Predator’s price. Some officials worried that adding encryption would make it harder to quickly share time-sensitive data within the U.S. military, and with allies.” # 17th December 2009, 7:36 am

Notes from the No Lone Zone. A computer scientist with a background in cryptography visits a Titan II ICBM launch complex. # 16th December 2009, 10:02 am

IE 6 and 7 hit by hack attack code. IE6 and 7 have what looks like a buffer overflow vulnerability caused by a strange intersection of CSS, innerHTML and large JavaScript arrays. No exploits in the wild yet but it’s only a matter of time. # 22nd November 2009, 3:38 pm

Major IE8 flaw makes ’safe’ sites unsafe. IE8 has an XSS protection feature which rewrites potentially harmful code in HTML pages—I think it looks for suspicious input in query strings which appears to have been output directly on the page. Unfortunately it turns out there’s a flaw in the feature that can allow attackers to rewrite safe pages to introduce XSS flaws. Google are serving all of their pages with the X-XSS-Protection: 0 header. Until the fix is released, that’s probably a good idea. # 22nd November 2009, 3:34 pm

Verified by Visa is training people to get phished. Searching for “Verified by Visa” on Twitter produces an endless stream of complaints. I don’t think I’ve ever heard anyone say anything good about it—and it certainly doesn’t make anything more secure. Presumably there’s some kind of legal liability benefit to it, though I imagine it benefits the card issuers rather than the consumer. # 11th November 2009, 10:47 am

Cross-domain policy file usage recommendations for Flash Player. One of the best explanations of the security implications of crossdomain.xml files I’ve seen. If you host a crossdomain.xml file with allow-access-from domain=“*” and don’t understand all of the points described here, you probably have a nasty security vulnerability. # 5th November 2009, 4:24 pm

Facebook and MySpace security: backdoor wide open, millions of accounts exploitable (via) Amazingly, both services had wide open holes in their crossdomain.xml files. Facebook were serving allow-access-from-domain=“*” in the crossdomain.xml file on one of their subdomains (a subdomain that still had access to the user’s profile information) while MySpace were opting in farm.sproutbuilder.com, a service which allowed anyone to upload arbitrary SWF files. # 5th November 2009, 9:47 am

Django security updates released. A potential denial of service vulnerability has been discovered in the regular expressions used by Django form library’s EmailField and URLField—a malicious input could trigger a pathological performance. Patches (and patched releases) for Django 1.1 and Django 1.0 have been published. # 10th October 2009, 12:24 am

XSS Protection by Default in Rails 3.0. Fantastic news—congratulations, Rails core team. # 8th October 2009, 4:35 pm

Adding signing (and signed cookies) to Django core. I’ve been increasing my participation in Django recently—here’s my proposal for adding signing and signed cookies to Django, which I’d personally like to see ship as part of Django 1.2. # 24th September 2009, 7:31 pm

Why Python Pickle is Insecure. Because pickle is essentially a stack-based interpreter, so you can put os.system on the stack and use it to execute arbitrary commands. # 9th September 2009, 11:04 pm

apache.org incident report for 8/28/2009. Various apache.org sites were down for a while last week—here the Apache Infrastructure Team provide a detailed description of what happened (a security breach on a minor server, which provided non-priveleged SSH access to mirror servers via an SSH key used for backups) and how they are responding. Useful for neophyte sysadmins like myself. # 3rd September 2009, 8:56 am

Facebook Hacked By 4chan, Accounts Compromised. It wasn’t Facebook that got hacked: 4chan members got hold of a list of usernames and passwords from an insecure Christian dating site and started using them to raise complete hell. Yet another demonstration that storing your user’s passwords in the clear is extremely irresponsible, and also a handy reminder that regular users who “don’t have anything worth securing” actually have a great deal to lose if their password gets out. # 23rd August 2009, 10:02 am

You Deleted Your Cookies? Think Again (via) Flash cookies last longer than browser cookies and are harder to delete. Some services are sneakily “respawning” their cookies—if you clear the regular tracking cookie it will be reinstated from the Flash data next time you visit a page. # 17th August 2009, 3:23 pm

Django: Security updates released. A fix for a directory traversal attack in the Django development server (the one with the big “never run this in production” warnings in the documentation). Also reminds that the release of 1.1 means that 0.96, released over two years ago, has reached end of life and will not receive any further bug fixes after the just-released 0.96.4. # 29th July 2009, 1:45 pm

The Anatomy Of The Twitter Attack. Long-winded explanation of the recent Twitter break-in, but you can scroll to the bottom for a numbered list summary. The attacker first broke in to a Twitter employee’s personal Gmail account by “recovering” it against an expired Hotmail account (which the attacker could hence register themselves). They gained access to more passwords by searching for e-mails from badly implemented sites that send you your password in the clear. # 20th July 2009, 12:55 am

Why an OAuth iframe is a Great Idea. Because users should a) learn to be phished and b) not even be given the option to avoid being phished if they know what they’re doing? No, no and thrice no. If you want to improve the experience, use a popup window so the user can still see the site they are signing in to in the background. # 16th July 2009, 8:29 pm

NaCl: Networking and Cryptography library. A new high level cryptography library. “NaCl advances the state of the art by improving security, by improving usability and by improving speed.” Ambitious claims, but DJB is one of the core maintainers. # 16th July 2009, 8:24 pm

Nmap 5.00 Release Notes. Released today, “the most important Nmap release since 1997”. New features include Ncat, a powerful netcat alternative, Ndiff, a utility for comparing scan results so you can spot changes to your network, and a new Nmap Scripting Engine using Lua. # 16th July 2009, 7:40 pm

Google asked people in Times Square:“What is a browser?”. Stuff like this makes me despair for creating a secure web—what chance do people have of surfing safely if they don’t understand browsers, web sites, operating systems, DNS, URLs, SSL, certificates... # 20th June 2009, 1:25 am

Cryptographic Right Answers. Best practise recommendations for cryptography: “While some people argue that you should never use cryptographic primitives directly and that trying to teach people cryptography just makes them more likely to shoot themselves in their proverbial feet, I come from a proud academic background and am sufficiently optimistic about humankind that I think it’s a good idea to spread some knowledge around.” # 11th June 2009, 10:16 pm