Hacker News Reader

Comment by tptacek | Hacker News Reader

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.

The vulnerabilities that command real dollars all have half-lives, and can't be fixed with a single cluster of prod deploys by the victims.

View on HN

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.

That's not how any of this works. A price for a vulnerability tracking the worst-case outcome of that vulnerability isn't a bounty or a market-clearing price; it's a shakedown fee. Meanwhile: the actual market-clearing price of an XSS vulnerability is very low (in most cases, it doesn't exist at all) because there aren't existing business processes those vulnerabilities drop seamlessly into; they're all situational and time-sensitive.

> the actual market-clearing price of an XSS vulnerability is very low (in most cases, it doesn't exist at all) because there aren't existing business processes those vulnerabilities drop seamlessly into; they're all situational and time-sensitive.

Could you elaborate on this? I don't fully understand the shorthand here.

I'm happy to answer questions but the only thing I could think to respond with here is just a restatement of what I said. I was terse; which part do you want me to expand on? Sorry about that!

> because there aren't existing business processes those vulnerabilities drop seamlessly into; they're all situational and time-sensitive.

what's an example of an existing business process that would make them valuable, just in theory? why do they not exist for xss vulns? why, and in what sense, are they only situational and time-sensitive?

i know you're an expert in this field. i'm not doubting the assertions just trying to understand them better. if i understand you're argument correctly, you're not doubting that the vuln found here could be damaging, only doubting that it could make money for an adversary willing to exploit it?

I can't think of a business process that accepts and monetizes pin-compatible XSS vulnerabilities.

But for RCE, there's lots of them! RCE vulnerabilities slot into CNE implants, botnets, ransomware rigs, and organized identity theft.

The key thing here is that these businesses already exist. There are already people in the market for the vulnerabilities. If you just imagine a new business driven by XSS vulnerabilities, that doesn't create customers, any more than imagining a new kind of cloud service instantly gets you funded for one.

Thank you, makes a lot of sense.

I wonder what you think of this, re: the disparity between the economics you just laid out and the "companies are such fkn misers!" comments that always arise in these threads on bounty payouts...

I've seen first hand how companies devalue investment in security -- after all, it's an insurance policy whose main beneficiaries are their customers. Sure it's also reputational insurance in theory, but what is that compared with showing more profit this quarter, or using the money for growth if you're a startup, etc. Basically, the economic incentives are to foist the risks onto your customers and gamble that a huge incident won't sink you.

I wonder if that background calculus -- which is broadly accurate, imo -- is what rankles people about the low bounty rewards, especially from companies that could afford more?

The premise that "fucking companies are misers" operate on that I don't share is that vulnerabilities are finite and that, in the general case, there's an existential cost to not identifying and fixing them. From decades of vulnerability research work, including (over the past 5 years) as a buyer rather than a seller of that work: put 2 different teams on a project, get 2 different sets of vulnerabilities, with maybe 30-50% overlap. Keep doing that; you'll keep finding stuff.

Seen through that light, bug bounty programs are engineering services, not a security control. A thing generalist developers definitely don't get about high-end bug bounty programs is that they are more about focusing internal resources than they are about generating any particular set of bugs. They're a way of prioritizing triage and hardening work, driven by external incentives.

The idea that Discord is, like, eliminating their XSS risk by bidding for XSS vulnerabilities from bounty hunters; I mean, just, obviously no, right?

How does stealing someone social media accounts not slot into "organized identity theft"?

... actually: how is XSS not a form of RCE? The script is code; it's executed on the victim's machine; it arrives remotely from the untrusted, attacker-controlled source.

And with the legitimate first-party's permissions and access, at that. It has access to things within the browser's sandbox that it probably really shouldn't. Imagine if a bank had used Mintlify or something similar to implement a customer service portal, for example.

You're misreading me. It's organized identity theft driven by pin-compatible RCE exploits. Is there already an identity theft ring powered by Mintlify exploits? No? Then it doesn't matter.

The subtlety here is the difference between people using an exploit (certainly they can) and people who buy exploits for serious money.

A remote code execution bug in ios is valuable - it may take a long time to detect exploitation (potentially years if used carefully), and even after being discovered there is a long tail of devices that take time to update (although less so than on android, or linux run on embedded devices that can’t be updated) That’s why it’s worth millions on the black market and apple will pay you $2 million dollars for it

An XSS is much harder to exploit quietly (the server can log everything), and can be closed immediately 100% with no long tail. At the push of an update the vulnerability is now worth zero. Someone paying to purchase an XSS is probably intending to use it once (with a large blast radius) and get as much as they can from it in the time until it is closed (hours? maybe days?)

> That's not how any of this works.

Yes, evidently not.

Just because on average the intelligence agencies or ransom ware distributors wouldn't pay big bucks for XSS on Zerodium etc. doesn't mean that's setting the fair, or wise price for disclosure. Every bug bounty program is mostly PR mitigation. It's bad PR if you underpay for a disclosed vulnerability, which may have ended your business, considering the price of security audits/practices you cheaped out on. I mean, most bug bounty programs are actually paid by scope, not market price for technically comparable exploits. If you found an XSS vulnerability in an Apple service with this scope, I bet you would have been paid more than 4k.

Nobody is buying anything on "Zerodium".

I wasn't aware they are gone. It's not my game, replace with whatever shady exploit trader/market out there.

I do not in fact think you would make a lot more than $4000, or even $4000 in the first place, for an Apple XSS bug, unless it was extraordinarily situationally powerful (for instance, a first-stage for a clean, direct RCE). Bounty prices have nothing at all to do with the worst-case damage a motivated actor could cause with a vulnerability.

https://security.apple.com/bounty/categories/

The lowest tier is $5k. XSS up to $40k. I think we're talking exfiltration of dev credentials...

Nice, I hadn't seen that. Well, there you go: the absolute most you're going to make for the absolute worst-case XSS bug at the largest software firm in the world.

Right, but Eva found an RCE and only got $5,000.

An RCE in what? Nobody's buying your Discord RCE.

Reply on news.ycombinator.com