While exploring a SaaS platform, I found a chain of behaviors that weren’t “bugs” on their own but created a real security weakness when combined:

Duplicate accounts allowed with the same phone number

Wallet credits transferable without proper permission checks

Payment-gated actions still possible without completing payment

Individually harmless.

Together = broken trust model.

Nothing crashed.

Nothing alerted.

But identity, permissions, and payments were no longer reliable.

This kind of issue doesn’t come from one bad function it comes from teams interpreting rules differently:

Product defines something one way

Engineering implements another

Support adds exceptions

Finance checks outcomes months later

Each part “works,” but the system as a whole becomes exploitable.

And the scary part?

All of it was discoverable from the frontend.

Questions for netsec:

How do you handle vulnerabilities caused by inconsistent assumptions instead of code errors?

Who owns these cross-system trust failures in your org?

Have you seen small logic gaps combine into a serious security flaw?

What’s the best way to report vulnerabilities created by inconsistent business rules?