[app.lemlist.com] Improper handling of payment lead to bypass payment

## Summary: Hello Team, I truly hope it treats you awesomely on your side of the screen :) due to improper handling of payment methods, an attacker can easily bypass the payment and benefit from a paid plan. ## Steps To Reproduce: 1. Log to your account 1. Go to the billing page 1. Fill in the address tab 1. Go to the next tab `Payment Card` 1. ==Now the interesting step Make sure you don't have any money on your credit card== 1. Chose `Email outreach` and wait until you get a notification that the payment is failed 1. Next increase the number of seats for example 50 1. Again you will get a notification that the payment is failed 1. Now Cancel the subscription 1. Now I can use the paid features without paying anything. # POC {{F1538593}} ## Impact I think the impact is pretty obvious, an attacker can use paid plans without paying anything. if you need more info feel free to ping me best Regards @omarelfarsaoui