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New Firefox security technology blocks Web attacks, Mozilla claims
- ax0n 17y agoUp next: New attack bypasses Firefox security technology, security researcher claims. I do infosec for a living. I can say with 100% certainty that the good guys are in a constant state of playing catch-up with the bad guys. The only thing we can hope for is to minimize the amount of time that serious vulnerabilities remain exposed, in hopes that it's fixed before someone creates yet another point-and-crack tool for the skiddies.
- tptacek 17y agoWithout saying why CSP is particularly susceptable to cat-and-mouse attacks, this comment doesn't have a lot of content. Do you have more thoughts to share about it?
- ax0n 17y agoSome big problems: It requires people to use firefox or for other vendors to adopt CSP, and it only works for sites that integrate it. Until it comes under attack, it's hard to say whether or not it'll fall victim to the cat-and-mouse thing or simply fail to gain traction. I haven't seen CSP in action, so my comment was tongue-in-cheek.
- tptacek 17y agoI don't really get CSP. Without changing anything in the browser, application developers --- the only people who can really use CSP --- can already create policies that say where dynamic code should or shouldn't be allowed. The problem is that modern web apps are riddled with places that need enough dynamicism that blunt filtering won't work.
- jfager 17y agoI don't think I understand what you're objecting to. The way I read it, CSP is lock-down by default (if the header is sent across to opt into it), with the application developer being responsible for providing a whitelist of where code and data can be loaded from. How can you do something similar today without still taking care to escape all inputs, etc.? http://people.mozilla.org/~bsterne/content-security-policy/details.html http://people.mozilla.org/~bsterne/content-security-policy/d...
- tptacek 17y agoThe libraries people use to "escape all inputs, etc" are providing effectively the same functionality as CSP is, but that's not my real concern. My real concern is, despite the fact that developers have the ability to set policies about what regions on the page can contain dynamic content, "policy" is generally too brittle to describe what people need to put on pages in real-world apps.
- jfager 17y agoThe libraries people use to "escape all inputs, etc" are providing effectively the same functionality as CSP is Maybe, but not everyone's using those libraries, and those libraries may themselves have bugs or may be used incorrectly. Defense-in-depth, and all that. "policy" is generally too brittle to describe what people need to put on pages in real-world apps Just reading through the spec I linked to, I don't see what would be particularly brittle about it. Do you have an example of a real-world use case that this would hamper?
- tptacek 17y agoSo, getting back to what I don't get about CSP, I don't see how anyone's more likely to use a new policy specification language better than they are going to use a toolkit designed for their own web framework. Brittleness: CSP disables <script> tags and all the script element attributes. Almost every major website in the world uses these in some form today. Both CSP and "anti-XSS" features do server-side policy about what parts of a page can have scripts, but the "anti-XSS" features are far more flexible.
- ax0n 17y agoAlso, it seems Computerworld believes it's similar to NoScript (which I use) whereas it really seems more like RequestPolicy (which I also use, but wouldn't wish upon anyone that's not equal parts sophisticated and paranoid)
- ajju 17y agoSpeaking of Mozilla security what is ex-Mozilla security chief Window Snyder upto? IIRC she used to work for Matasano previously but if she has started a new startup I'd like to keep an eye on that!
- tptacek 17y agoShe'll be out here in a week for our crypto-for-penetration-testers class, so I'm happy to ask her.