u/Technical-Log4868

You build an app with AI over a weekend. It works. people sign up. Then one afternoon a user emails and asks why they can see someone else's invoice when they change the number in the link.

That is not a rare story. earlier this year a popular AI app builder had a bug where any free account could pull other people's source code, database keys, and private chats. On one AI app marketplace, roughly one in ten apps were quietly leaking user data the same way. Same root cause every time.

The bug has a boring name (people call it BOLA or IDOR) and a simple meaning. One logged-in user can reach another user's stuff. Your app checks that you are logged in. It forgets to check that the thing you are asking for is actually yours. The AI writes the part that makes the feature work and quietly skips the part that asks "wait, is this yours?" So the app looks perfect in the demo and leaks in production.

Here is the annoying part. A code scanner cannot really see this. It is not a bad word sitting in your code, it is a missing check in a live request. A one time audit checks the day it runs, then you ship ten more changes the next week.

The good news is you can test for it yourself in about two minutes:

1. Make two accounts in your own app. Call them A and B.
2. Log in as A and open something private. A note, an order, a profile. Look at the id in the address bar or the network request, something like /api/orders/1042.
3. Now log in as B and ask for A's exact thing. Same /api/orders/1042.
4. If B gets A's data back, you have the bug. If B gets blocked, that endpoint is fine. Repeat on your other main screens.

The fix is one idea. On the server, every time you read or change a record, check that the record belongs to the logged in user. Not just that they are logged in, that this specific row is theirs. Never trust the id coming from the browser.

I run into this constantly in AI-built apps, and almost nobody checks until a user finds it first. Curious how many of you have actually run this test on your own app and what you found. And if you have a cleaner way to check across a whole app, I want to hear it.

Built this and I want it torn apart, this sub seems like the right place. It's called BoLD and it does one thing, it checks whether your app leaks one user's private data to another (a logged-in user changes an ID in a request and gets back someone else's record). It's live and free.

Point it at your own app and roast whatever's bad, the onboarding, the speed, the result, the explanation, the trust factor of running it near your auth, all of it. I'd rather you find the flaws than a prospect.

Link: https://www.boldsec.io/

Genuinely, the harsher the better. What made you not trust it, or not bother finishing? That's the stuff I need to hear.

something worth knowing if you run a SaaS, especially one built fast or with AI tools. The single most common API vulnerability is embarrassingly simple your app checks that a user is logged in, but never checks that the specific record they're asking for actually belongs to them. So a logged-in user changes an ID in a request (say /invoice/123 to /invoice/124) and the app hands back a stranger's data. No error, no log. It looks perfect in every demo because you only ever open your own data. It breaks the day a real user reaches someone else's.

how to check your own app in a few minutes, no tools needed: make two test accounts, A and B. As B, create a record and note its ID. Then, logged in as A, request B's record directly (change the ID in the URL or API call). If you get B's data back instead of a 403, you have the hole. try it on read, then on update and delete, those are often worse.

The fix is usually one line enforce ownership on the server (check the record belongs to the current user), or on Supabase, enable row-level security so every query is scoped automatically.

I've been going deep on this problem for a while (I built something around it), so happy to answer questions in the comments if anyone wants help interpreting what they find or figuring out the fix for their stack. :)

Just launched the beta of something I couldn't stop thinking about, and it's fully live, so you can point it at your own app right now and see for yourself.

Here's the problem it catches. Most apps check that a user is logged in, but forget to check that the specific data they're asking for actually belongs to them. So a logged-in user changes one number in a request, and the app quietly hands back a stranger's record. It's the most common API vulnerability; it's behind real breaches you've read about this year, and the unsettling part is it looks completely fine in every demo, because you only ever open your own data. It breaks silently the first time a real user reaches someone else's.

The tool runs a check on your live app and shows you, in plain English, whether this hole exists, the exact request, what it means, and the one-line fix. It uses only test accounts, so it proves you're exposed without ever touching your real users' data.

I'll be honest about where it is. It's early, and right now it does this one thing on purpose, catches the "reaching data you don't own" family of flaws, and does it well. I'd rather nail one dangerous, common thing than throw fifty vague warnings at you that you'd ignore. The bigger idea is a live layer that watches for the whole class of "this request shouldn't have worked" as your app grows, but I wanted the first piece to genuinely earn its place before promising the rest.

It's free right now. If you run a real app, take two minutes and check it: https://www.boldsec.io/

Whatever it finds, I'd love to hear how it went, especially if it finds nothing, or if something felt off. Honest reactions are the whole reason I'm posting :)

Something's been bugging me since I started building small apps with AI tools, and I finally built something to deal with it, so I want to sanity-check the problem with people who actually run live SaaS.

Here's the trap. You test your app with your own account, your own data. Everything works. You ship. What you never test is what happens when a different logged-in user changes one number in a request and asks for a record that isn't theirs. A huge number of AI-built apps will just hand it over, because the app checked that the person is logged in but never checked that the data belongs to them. No error, no log, nothing tells you. It only breaks the day a real user (or a curious one) reaches someone else's data. And by then it's a breach, not a bug.

The thing that gets me is it's invisible to the person who built it. From your side the app looks flawless forever...!

I built a tool that watches for exactly this and tells you, in plain English, the moment it could happen, with the exact request and the fix. It's deliberately narrow right now, it catches this one family of "reaching data you don't own" flaws and catches it well, rather than being another dashboard of 50 warnings you'd ignore. That's step one of a bigger idea, but I wanted the first piece to be genuinely useful on its own.

Honest question for this sub: do you actually test for this, or is it one of those things you assume the framework/AI handled? I'm trying to figure out if founders quietly worry about this or never think about it at all. And if you want, I'll check your live app for this specific bug for free, test accounts only, and just show you what I find. Link in a comment...

sharing this to get it torn apart, because i can't tell if it's a real company or just a feature.

the problem: tons of people now build real apps with AI tools (lovable, bolt, cursor) without knowing how to code. there's a bug that shows up in these constantly. the app checks that you're logged in, but forgets to check that the data you're requesting actually belongs to you. so any logged-in user can see another user's private data by changing a number in the URL (/invoice/104 → 105). it caused the real Lovable and Tea breaches.

what makes it nasty: it's invisible to the person who built it. their app works perfectly when they test it, because they only ever look at their own account. and the fix is in server code they literally can't read. so it just sits there leaking, for months, until a customer or a hacker finds it.

the idea: a tool that watches for exactly this, live, and tells the non-technical founder in plain english "someone just accessed data they shouldn't have, here's the fix" without ever touching their real users' data. like a smoke detector for data leaks, for people who can't audit their own code.

where i'm genuinely unsure, and want the brutal version:

1. is this a real company or just a feature a platform like lovable bolts on next year?

2. would a non-technical founder actually pay for this, or only care after they've already been breached?

3. is "they only care after they're burned" a dealbreaker for this whole thing?

built a rough working version that catches the bug. not selling anything, genuinely want to know if the business logic holds or if i'm fooling myself.

sharing this to get it torn apart, because i can't tell if it's a real company or just a feature.

the problem: tons of people now build real apps with AI tools (lovable, bolt, cursor) without knowing how to code. there's a bug that shows up in these constantly. the app checks that you're logged in, but forgets to check that the data you're requesting actually belongs to you. so any logged-in user can see another user's private data by changing a number in the URL (/invoice/104 → 105). it caused the real Lovable and Tea breaches.

what makes it nasty: it's invisible to the person who built it. their app works perfectly when they test it, because they only ever look at their own account. and the fix is in server code they literally can't read. so it just sits there leaking, for months, until a customer or a hacker finds it.

the idea: a tool that watches for exactly this, live, and tells the non-technical founder in plain english "someone just accessed data they shouldn't have, here's the fix" without ever touching their real users' data. like a smoke detector for data leaks, for people who can't audit their own code.

where i'm genuinely unsure, and want the brutal version:

1. is this a real company or just a feature a platform like lovable bolts on next year?
2. would a non-technical founder actually pay for this, or only care after they've already been breached?
3. is "they only care after they're burned" a dealbreaker for this whole thing?

built a rough working version that catches the bug. not selling anything, genuinely want to know if the business logic holds or if i'm fooling myself.

sharing this to get it torn apart, because i can't tell if it's a real company or just a feature.

the problem: tons of people now build real apps with AI tools (lovable, bolt, cursor) without knowing how to code. there's a bug that shows up in these constantly. the app checks that you're logged in, but forgets to check that the data you're requesting actually belongs to you. so any logged-in user can see another user's private data by changing a number in the URL (/invoice/104 → 105). it caused the real Lovable and Tea breaches.

what makes it nasty: it's invisible to the person who built it. their app works perfectly when they test it, because they only ever look at their own account. and the fix is in server code they literally can't read. so it just sits there leaking, for months, until a customer or a hacker finds it.

the idea: a tool that watches for exactly this, live, and tells the non-technical founder in plain english "someone just accessed data they shouldn't have, here's the fix" without ever touching their real users' data. like a smoke detector for data leaks, for people who can't audit their own code.

where i'm genuinely unsure, and want the brutal version:

1. is this a real company or just a feature a platform like lovable bolts on next year?

2. would a non-technical founder actually pay for this, or only care after they've already been breached?

3. is "they only care after they're burned" a dealbreaker for this whole thing?

built a rough working version that catches the bug. not selling anything, genuinely want to know if the business logic holds or if i'm fooling myself.

been building with ai tools for a while and kept hitting the same scary bug in my own stuff, so figured i'd write up how to check for it because i don't see it talked about much here.

the bug: your app checks that someone is *logged in*, but never checks that the thing they're asking for actually *belongs to them*.

concrete example. say you open one of your own records and the url looks like /orders/104. out of habit you change it to 105. if you can now see someone else's order, that's the bug. auth passed (you're logged in), but ownership was never checked. it happens constantly in ai-generated backends because the model writes the "are you logged in" check and just quietly never writes the "do you own this" check. the two look almost identical in code so the second one gets skipped.

the reason it's so easy to miss: it's invisible when you test your own account. everything works, every record loads, looks perfect. it only breaks when a *second* user requests a *first* user's data, and you never play the second user while building your own thing.

how to check yours (takes 2 min):

* make two accounts, A and B
* as A, create a record (a note, an order, whatever) and grab its id from the url or network tab
* log in as B, and try to open A's record by its id
* also try editing and deleting it, not just viewing
* if B can see or touch A's stuff, you've got it

the fix isn't hiding the id or switching to random uuids (that just makes it harder to guess, the hole's still there). the real fix lives on the server: every query has to be scoped to the current user, or use row-level security so the db itself refuses. if you're on supabase specifically, this is the RLS-disabled-by-default thing that bites a lot of people.

i got obsessed enough with this that i ended up building a little script to automate the two-account check, but honestly the manual version above catches it fine for most apps. mostly just wanted more people to know the check exists before they find out the hard way.

happy to answer questions in the comments if anyone's unsure whether their setup is exposed.

This has been sitting with me for a few weeks and I think someone here needs to read it before it happens to them.

I was poking around a small SaaS built almost entirely with [Lovable]. Real product, real users. I was clicking through, looking at one record, and I noticed the URL had the record's ID sitting right there in it. Something like /clients/104. Out of pure habit I changed it to 105.

It loaded... Someone else's client. Full details. I changed it again. Another stranger. I just kept going.

I want to be clear about what that means. This was not a hack. I did not use any tools. I was logged in as a normal user and I was reading every other user's private data by typing different numbers. And it had been live like that for weeks. Anyone who got curious the way I did could have done the exact same thing, and nobody would have ever known.

When I looked at why, it honestly turned my stomach, because it is so simple. The AI wrote code that checked whether you were logged in. It never checked whether the thing you were asking for actually belonged to you. And here is the part that gets everyone: those two checks look almost identical when you read the code, so the second one just quietly never gets written. The tool does not warn you. The app works perfectly in every demo. It only breaks the day someone types 105.

I am posting because I do not want you to find this the way I did, or worse, find out from a furious user or a screenshot doing the rounds.

So please take five minutes tonight and check your own app:

Make two accounts, A and B. Log in as A. Open one of your own records and look at the URL or the network tab for an ID. Now put in an ID that belongs to B. If you can see B's stuff while logged in as A, you have the hole. Try it anywhere you have things keyed by an ID. Orders, profiles, messages, uploads, invoices.

If you run this and your stomach drops, you are really not alone. This is probably the single most common flaw in AI-built apps right now. Drop a comment or DM me and I will help you make sense of what your tool actually generated and how to close it. No catch. I have just been buried in this and would rather it be useful to someone....

(Honest note: I have gotten a bit obsessed with this problem and I am poking at whether there is a tool worth building around it. That is genuinely not why I am posting, and there is nothing to buy. The check above is the whole point.)

Last week I spent ~40 min re-explaining an auth setup to Cursor that I'd already figured out with Claude three days earlier. Claude knew the whole
history. Cursor knew nothing. It even suggested the exact token-refresh fix I'd already ruled out. Felt like onboarding a new contractor every session.

This happens constantly. ChatGPT for planning, Claude for the hard stuff, Cursor in the editor, and each tool only knows its own slice. The actually
useful part (why we rejected an approach, which fix actually worked, what's already been tried) is buried in chats I'll never scroll back through.

I came close to building a tool for this. Then I talked myself out of it, and I genuinely can't tell if I'm right to quit. My own case against it:

- markdown + git already solves like 80% of this, for free
- Claude has Projects/memory, Cursor has memory, they'll probably just absorb it
- there are already a few OSS tools doing it
- and half the value of a status.md is that writing it forces you to think. automate that and the file rots into noise within a month.

So I'm not asking "is this a real pain" (I know it is).

The uncomfortable version:

What do you actually do about it today? And has anyone here ever PAID for a tool that fixes this, or tried one and dropped it? If you dropped it, why?

Trying to figure out if this is a real wallet problem or just a thing we all complain about and route around with a markdown file…

I'm validating a problem I keep running into as a developer.

When I'm building something with Al, I usually jump between ChatGPT, Claude, Cursor, and sometimes Gemini. One tool helps better with architecture, another is better for debugging, another is better inside the IDE.

The annoying part is that none of them know what happened in the other tool.

The useful knowledge is usually buried in old chats: architecture
decisions
bugs and fixes
failed
approaches
setup instructions constraints
next steps

The current workaround is usually markdown files, Notion, README notes, or manually pasting summaries into each new chat.

I'm wondering if this is a real enough pain to build around.

Would developers actually use or pay for a local-first project memory layer that keeps Al coding context organized across tools?

Or is this something most people would just solve with a markdown file?