Simon Willison’s Weblog

Items tagged security in Nov

Filters: Month: Nov × security ×


From Markdown to RCE in Atom (via) Lukas Reschke found a remote code execution vulnerability in the Atom editor by taking advantage of a combination of Markdown’s ability to embed HTML, Atom’s Content-Security-Policy allowing JavaScript from the local filesystem to be executed, and a test suite HTML file hidden away in the Atom application package that executes code passed to it via query string. # 23rd November 2017, 4:13 pm

Introducing security alerts on GitHub. This is huge: GitHub’s dependency graph feature now shows any dependencies that have a known security vulnerability, based on CVE IDs—and you can sign up for notifications of new vulnerabilities as well. Only supports Ruby and JavaScript today, but Python support is coming in 2018. # 16th November 2017, 7:48 pm

Is there anyway to game unique link verifications?  Like when you get sent a link of the form https:/........com/UID=TYYN04001 How would one change the digits to reproduce another working link?

Not if they’ve been implemented correctly.

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How could GitHub improve the password security of its users?

By doing exactly what they’re doing already: adding more sophisticated rate limiting, and preventing users from using common weak passwords.

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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

The March of Access Control. The W3C Access Control specification is set to become a key technology in enabling secure cross-domain APIs within browsers, and since it addresses a legitimate security issue on the web I hope and expect it will be rolled out a lot faster than most other specs. # 19th November 2008, 8:40 am

Worst. Bug. Ever. Android phones were executing every keystroke typed in to the phone in an invisible root shell! Text “reboot” to a friend and your phone rebooted. Wow. # 10th November 2008, 10:51 pm

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

.. yet another ridiculous data breach: this time, people’s passwords to the Government Gateway on a memory stick dropped in the road. Perhaps it is uncouth to point this out, but... if the system had been designed by people with any security clue whatsoever there would have been no passwords to put on a memory stick in the first place.

Ben Laurie # 2nd November 2008, 1:04 pm

Why Virtual Theft Should Matter to Real Life Tech Companies. Interesting trend: sites that profit from sales of virtual goods (such as Habbo Hotel) are seeing users use phishing attacks to steal those goods from each other. # 18th November 2007, 11:21 am

I don’t understand why the NSA was so insistent about including Dual_EC_DRBG in the standard. It makes no sense as a trap door: It’s public, and rather obvious. It makes no sense from an engineering perspective: It’s too slow for anyone to willingly use it. And it makes no sense from a backwards-compatibility perspective: Swapping one random-number generator for another is easy.

Bruce Schneier # 16th November 2007, 10:25 am

Django Changeset 6671. Malcolm Tredinnick: “Implemented auto-escaping of variable output in templates”. Fantastic—Django now has protection against accidental XSS holes, turned on by default. # 14th November 2007, 5:05 pm

In the long term, I want to replace JavaScript and the DOM with a smarter, safer design. In the medium term, I want to use something like Google Gears to give us vats with which we can have safe mashups. But in the short term, I recommend that you be using Firefox with No Script. Until we get things right, it seems to be the best we can do.

Douglas Crockford # 7th November 2007, 3:36 pm

Zero-Day Exploit Targets IE (via) Remote code execution. No patch yet; disable Active Scripting instead. # 22nd November 2005, 6:24 am

Social engineering and Orange

I had a call on my mobile earlier today from a lady claiming to be from Orange (my phone service provider) who told me that my contract was about to expire. She asked me for my password.

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The Register hit by XSS

Here’s a nasty one: popular tech news site The Register was hit on Saturday by the Bofra exploit, a nasty worm which uses an iframe vulnerability in (you guessed it) Internet Explorer to install nasty things on the victim’s PC. Where it gets interesting is that the attack wasn’t against the Register themselves; it came through their third party ad serving company, Falk AG.

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User Education Is Not the Answer to Security Problems. Smart thinking on security from Jakob Nielsen. # 1st November 2004, 1:22 pm

High security is low security

Via Crypto-Gram, a great piece from Bruce Tognazzini about how tough security measures can actively reduce the security of a system:

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XML security on SitePoint

Getting Started with XML Security is a SitePoint article of epic proportions. I had never really looked at any of the XML security applications but this article appears to cover the lot.

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OWASP Security guide

The Open Web Application Security Project (OWASP) have a free guide to building secure web applications, which covers a large range of common problems such as cross site scripting and SQL injection vulnerabilities. The report is a 60 page PDF and although I haven’t had time to go through it yet it looks like an excellent read.

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