Subject: Re: [bitcoin-dev] Full Disclosure: CVE-2023-40231 / CVE-2023-40232 / CVE-2023-40233 / CVE-2023-40234 "All your mempool are belong to us"

From: Peter Todd <[email-masked]>
Date: Mon, 16 Oct 2023 21:13:52 +0200

On October 16, 2023 6:57:36 PM GMT+02:00, Antoine Riard via bitcoin-dev <[email-masked]> wrote:
>(cross-posting mempool issues identified are exposing lightning chan to
>loss of funds risks, other multi-party bitcoin apps might be affected)
>
>As the HTLC-preimage spends an unconfirmed input that was already included
>in the unconfirmed and unrelated child transaction (rule 2), pays an
>absolute higher fee of at least the sum paid by the HTLC-timeout and child
>transaction (rule 3) and the HTLC-preimage feerate is greater than all
>directly conflicting transactions (rule 6), the replacement is accepted.
>The honest HTLC-timeout is evicted out of the mempool.

I think if you want people to understand this exploit, you need to explain in more detail how we have a situation where two different parties can spend the same HTLC txout, without the first party having the right to spend it via their knowledge of the HTLC-preimage.