Ask HN: How do you make sure js from a CDN or a CMS hasn't changed?

2 points·swlkr··6 comments

After seeing the magecart attacks at BA and Newegg I decided to try and build a solution: https://magehash.com, unsure if it's useful yet, what do you think?

I'm thinking about integrating it in existing CI/CD workflows, to avoid false positives too

Not sure if this is what you're looking for, but subresource integrity perhaps?

https://hacks.mozilla.org/2015/09/subresource-integrity-in-f...

I did see subresource integrity, but I was also curious about last month's string of high profile magecart vulnerabilities, would subresource have saved them there, or is there more to it?

SRI won't protect you from:

* Someone injecting malicious JS code into your checkout page

* Non-static JS includes like Google Analytics

But it works well for static assets like jQuery or other static JS resources.

I was working with OP on a static asset integrity tool and testing I found out google analytics and facebook change their code multiple times a day!

It's been interesting working with teams that have well-defined release management workflows and continuous integration with snapshotted npm/mvn dependencies, but still allow a third party like GA to inject JS that skips the QA queue.

Likewise with CloudFlare: Allowing a third party to proxy all your traffic is a huge liability. CloudBleed should have been a wake-up call, but it doesn't seem to have had much effect.

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