Minor DoS vulnerability in BIP144 lack of tx witness data size limit



Summary:

A recent multisig segwit transaction has highlighted a problem with BIP144. The solution applied for btcd shows that effectively a single transaction witness can be the same as the maximum block size. While 11000 bytes may not be unreasonable, there is now a special case with a block over 33k worth of witness data. A concrete limit should be set on the maximum size of a transaction witness and this should be discussed in a more general sense about total transaction sizes.Without a specification, it becomes impossible to properly implement and the status quo devolves to the actual implementation in the bitcoin core repository code. Therefore, a discussion is needed to set a concrete limit on the maximum size of a transaction witness.The weight calculation should escalate exponentially to discourage putting transactions like this on the chain. The price was equivalent to about $5 to do this.


Updated on: 2023-05-22T21:31:14.053010+00:00