Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

We pwned X, Vercel, Cursor, and Discord through a supply-chain attack

gist.github.com

Post reply on HN
Print view View original

61–70 of 453 posts

Re: We pwned X, Vercel, Cursor, and Discord through a supply-chain attack

#61

Post by jeffjeffbear »

JackSlateur wrote: post #39

I struggle to understand the issue .. could someone help me out ? Ok, you got " https://discord.com/_mintlify/_static/hackerone-a00f3c6c/lma... " to send a controlled payload But regular users will never hit " https://discord.com/_mintlify/_static/hackerone-a00f3c6c/lma... ", so they will never execute your script I fail to understand how this can be exploited, by whom and in what conditions

You have control over what displays on a page with a discord.com domain, you could manipulate the dom to have a login or something else and have it pass the data to your servers. A user would just see a link from discord.com

Re: We pwned X, Vercel, Cursor, and Discord through a supply-chain attack

#62

Post by jijijijij »

tptacek wrote: post #42
padjo wrote: post #4

Seems like such a tiny amount of money for a bug that can be used to completely own your customers accounts. Also not much excuse for xss these days.

This comes up on every story about bug bounties. There is in general no market at all for XSS vulnerabilities. That might be different for Twitter, Facebook, Instagram, and TikTok, because of the possibility of monetizing a single strike across a whole huge social network, and there's maybe a bank-shot argument for Discord, but you really have to do a lot of work to generate the monetization story for any of those. T…

If a $500 drone is coming for your $100M factory, the price limit for defense considerations isn't $500.

In the end, you are trying to encourage people not to fuck with your shit, instead of playing economic games. Especially with a bunch of teenagers who wouldn't even be fully criminally liable for doing something funny. $4K isn't much today, even for a teenager. Thanks to stupid AI shit like Mintlify, that's like worth 2GB of RAM or something.

It's not just compensation, it's a gesture. And really bad PR.

Re: We pwned X, Vercel, Cursor, and Discord through a supply-chain attack

#63

Post by llmslave2 »

tptacek wrote: post #41
llmslave2 wrote: post #22

This feels so emblematic of our current era. VC funded vibe coded AI documentation startup somehow gets big name customers who don't properly vet the security of the platform, ship a massive vulnerability that could pwn millions of users and the person who reports the vulnerability gets...$5k. If I recall last week Mintlify wrote a blog post showcasing their impressive(ly complicated) caching architecture. Pretending…

I don't think anybody in SFBA-style software development, both pre- and post-LLM, is really resilient against these kinds of attacks. The problem isn't vibe coding so much as it is multiparty DLL-hell dependency stacks, which is something I attribute more to Javascript culture than to any recent advance in technology.

You're right that it's a specific programming culture that is especially vulnerable to it. And for the same reasons they were vulnerable to the same thing to a lesser degree before the rise of LLMs.

But like, this case isn't really a dependency or supply chain attack. It's just allowing remote code execution because, idk, the dev who implemented it didn't read the manual and see that MDX can execute arbitrary code or something. Or maybe they vibe coded it and saw it worked and didn't bother to check. Perhaps it's a supply-chain attack on Discord et al to use Mintlify, if thats what you meant then I apologize.

I think you're right that I have an extreme aversion to SFBA-style software development, and partly because of how gen-ai is used there.

Re: We pwned X, Vercel, Cursor, and Discord through a supply-chain attack

#64

Post by hackermondev »

rainonmoon wrote: post #58
JackSlateur wrote: post #39

I struggle to understand the issue .. could someone help me out ? Ok, you got " https://discord.com/_mintlify/_static/hackerone-a00f3c6c/lma... " to send a controlled payload But regular users will never hit " https://discord.com/_mintlify/_static/hackerone-a00f3c6c/lma... ", so they will never execute your script I fail to understand how this can be exploited, by whom and in what conditions

You're pretty much on the money. Reflected XSS requires social engineering to really target anyone without other primitives. Unfortunately this report is not very clear about the tangible impacts or limitations of what they could do with this particular XSS either. Saying that every Mintlify customer was "vulnerable to account takeover with a single malicious link" strikes me as specious to say the least. Still, can'…

imo, the impact is pretty clear here. an unsuspecting user clicks (or is redirected) to one of these malicious links on the platform (ex. vercel); the script grabs their cookie and credentials and sends it to the attacker. they now have full access to the victim's account.

Re: We pwned X, Vercel, Cursor, and Discord through a supply-chain attack

#65

Post by wonnage »

JackSlateur wrote: post #39

I struggle to understand the issue .. could someone help me out ? Ok, you got " https://discord.com/_mintlify/_static/hackerone-a00f3c6c/lma... " to send a controlled payload But regular users will never hit " https://discord.com/_mintlify/_static/hackerone-a00f3c6c/lma... ", so they will never execute your script I fail to understand how this can be exploited, by whom and in what conditions

You could send that link to an unsuspecting user and steal their cookies, make API requests to send messages on their behalf, etc

Apparently one of the other linked posts shows how you can also gain RCE, since the docs are statically pre-rendered and there’s no sandboxing to prevent you from evalling arbitrary JavaScript.

Re: We pwned X, Vercel, Cursor, and Discord through a supply-chain attack

#66

Post by ajross »

FeepingCreature wrote: post #16
dllu wrote: post #5

The fact that SVG files can contain scripts was a bit of a mistake. On one hand, the animations and entire interactive demos and even games in a single SVG are cool. But on the other hand, it opens up a serious can of worms of security vulnerabilities. As a result, SVG files are often banned from various image upload tools, they do not unfurl previews, and so on. If you upload an SVG to discord, it just shows the raw…

If only there was a widely used vector format that had script support and also decades of work on maintaining a battle-tested security layer around it with regular updates on a faster release cycle than your browser. That'd be crazy. Sure would suck if we killed it because we didn't want to bother maintaining it anymore. (Yes I'm still salty about Flash.)

Uh... Flash was a genuine firehose of security flaws. I mean, yeah, they patched them. So "battle tested security layer" isn't wrong in a technical sense. But, yikes, no.

Re: We pwned X, Vercel, Cursor, and Discord through a supply-chain attack

#68

Post by tptacek »

jfindper wrote: post #59
tptacek wrote: post #47

Earlier quoted context omitted.

What "grey market" are you talking about? How specific can you be about it?

[flagged]

There absolutely is. I'm just not familiar with one that buys these vulnerabilities.

Re: We pwned X, Vercel, Cursor, and Discord through a supply-chain attack

#69

Post by orliesaurus »

I've been following the rise of SVG based attacks recently... It's not just hypothetical anymore... People are using SVG files to deliver full phishing pages and drive by downloads by hiding JavaScript in the markup

ALSO as someone who maintains a file upload pipeline I run every SVG through a sanitizer... Tools like DOMPurify remove scripts and enforce a safe subset of the spec... I even go as far as rasterizing user uploaded vectors to PNG when possible

HOWEVER the bigger issue is mental... Most folks treat SVG like a dumb image when browsers treat it like executable content... Until the platform changes that expectation there will always be an attack surface

Re: We pwned X, Vercel, Cursor, and Discord through a supply-chain attack

#70

Post by rainonmoon »

hackermondev wrote: post #64
rainonmoon wrote: post #58

Earlier quoted context omitted.

You're pretty much on the money. Reflected XSS requires social engineering to really target anyone without other primitives. Unfortunately this report is not very clear about the tangible impacts or limitations of what they could do with this particular XSS either. Saying that every Mintlify customer was "vulnerable to account takeover with a single malicious link" strikes me as specious to say the least. Still, can'…

imo, the impact is pretty clear here. an unsuspecting user clicks (or is redirected) to one of these malicious links on the platform (ex. vercel); the script grabs their cookie and credentials and sends it to the attacker. they now have full access to the victim's account.

Nice! So the Cookie is accessible by JavaScript on all of those sites? That would be pretty surprising given the prevalence of HttpOnly, so that doesn't seem clear to me at all. And they're all using Cookie-based auth, you think? You're a bug bounty hunter so I'll defer to your wisdom, but doesn't it seem more likely that an account takeover would be possible via a state-changing request from the user's existing session? Let's say they can abuse it to reset the user's password. Nice, that's an account takeover... for every user not using MFA. But then there are anti-CSRF mitigations. Okay, not insurmountable with an XSS, but implemented differently everywhere. And what if the auth domains are separate to the domain on which the XSS is triggered? Man this seems to get less clear by the minute. Please clear this up for me.
Post reply on HN