Hi guys, i have a question.
Is recursive reentrancy possible when contract A sends ether to contract B via .transfer() and then Contract B call contract A again recursively (before contract A function is completed) to drain contract A balances? I have read the solidity docs and there is stated that ether sent via send() and transfer() functions can rely on 2300 gas only. I have written POC and when i call contract A recursively on ether recived in contract B, it only works for 1 iteration, if there are more than 1 iterations tx reverts.

Sep 5, 2023, 8:58 AM

as you said
transfer is capped to 2300 gas

Sep 5, 2023, 9:38 AM

so no recursive reentrancy possibility in that case, right?

Sep 5, 2023, 9:38 AM

not at the same level of .call()

Sep 5, 2023, 9:39 AM

my fear is that contract A changes balances state variable after the .transfer() thats why i am asking, but whatever i do i was only able to do 1 iteration, so the balances was also changed

Sep 5, 2023, 9:40 AM

can you share a screenshot

Sep 5, 2023, 9:40 AM

yeah sec

Sep 5, 2023, 9:40 AM

reentrancy can be avoid easily
just need to write good code

Sep 5, 2023, 9:41 AM

this is from contract A

this is from contract B

Sep 5, 2023, 9:43 AM

burn before transfering eth

Sep 5, 2023, 9:45 AM

yeah, will do that but is the reentrancy possible and drain the available eth in contract A? according to solidity docs as far i understood no?

Sep 5, 2023, 9:46 AM

depends on how many ETH you send at each iteration

Sep 5, 2023, 9:57 AM