AliExpress and similar

Miri

I managed to sign up on Aliexpress and opon sign in aliexpress signed me in with my old account that i used with a different phone.
My old phone was a Xiaomi runing official hyper os and my new phone is a pixel 8 pro runing gos, the two phones had never transitioned anything between them and yet Aliexpress find out that im the same person.
On gos Aliexpress hat only the network permission and downloaded from aurora store

de0u

Miri I managed to sign up on Aliexpress and opon sign in aliexpress signed me in with my old account that i used with a different phone.

What information is provided during the signup process? Is a text message sent to a phone number?

Miri

@de0u i haven't assigned a phone number to the old account and also to the new account, what was strange was that i struggled to sign up and entered my proton mail (my old account was a gmail) and a random password and hoping to redirect me to sign up page instead it sent me an email to proton with an OTP, I've entered that and showed me the fields to set up a new password and after doing that I've entered the new email and new password to the app and instantly the app showed me my orders that ive made with the old account.
After experiencing this ( my old account was in and xiaomi device and my new account is created from GOS in a pixel device, the only connection between this 2 phones is the WiFi access point and nothing else) i was wandering is GrapheneOS that secure?

nologo

Miri i haven't assigned a phone number to the old account and also to the new account, what was strange was that i struggled to sign up and entered my proton mail (my old account was a gmail) and a random password and hoping to redirect me to sign up page instead it sent me an email to proton with an OTP, I've entered that and showed me the fields to set up a new password and after doing that I've entered the new email and new password to the app and instantly the app showed me my orders that ive made with the old account.

So you did not create a new account, but changed the username and password of the existing one...

Miri

@nologo again, how did Aliexpress know what account to change the usename and password?!

de0u

Miri How did Aliexpress know what account to change the usename and password?!

I'm not sure enough information has been presented so far. For example, we don't have screenshots of all of the steps, but also we don't have information on various possible ways AliExpress might have been able to tie the devices together. If a phone number was used on the two phones that could have been part of a connection. If both devices were signed in to an account on some other Alibaba property (TaoBao, Cainiao, etc.), that might do it.