Lightning Network: a bug in the Bitcoin second layer

A popular bills network going for walks atop the bitcoin blockchain suffered from an extended-status code vulnerability – one in which attackers ought to drain customers’ of their money.
While initially flagged to the public on Aug. 30 by means of bitcoin developer Rusty Russell, the whole disclosure detailing how this vulnerability may be exploited by an attacker turned into released Friday.

“An attacker can declare to open a [lighting payments] channel but both now not pay to the peer, or not pay the whole amount,” Russell wrote inside the full disclosure.

The lightning network is a Layer 2 bills protocol allowing ultra-speedy and nearly costless transactions atop the bitcoin blockchain. In order for customers to ship transactions throughout the lightning community, they ought to open what are called “bills channels” to send and receive budget from other lightning customers.

Without the proper checks, an attacker ought to fake to open a new bills channel and send fake transactions. Being duped, an honest person may want to then ship returned actual cash to the attacker no longer knowing the previous transactions had been completely artificial. It’s doubtful what number of users fell victim to such attacks.

Already, all principal lightning software program customers have been upgraded to restore this vulnerability, according to Russell.

When requested why it took 3 months for the vulnerability to be disclosed to users, Pierre-Marie Padiou – the CEO of a business enterprise keeping one of the 3 most popular lightning implementations – stated developers needed to err at the facet of warning.

“The hassle with this vulnerability is that once you realize about it, it appears so apparent,” stated Padiou. “Three months isn’t always a long term. It’s a quite brief time due to the fact you have to supply customers the quantity of time needed to update. … A lot of users don’t do it.”

Lightning developers, he brought, did not need to risk revealing the vulnerability until genuinely certain no customers had been at risk.

“There are continually issues. Even on the bitcoin protocol, there were insects,” Padiou said, including:

“There will always be bugs. What matters the most is how to handle this in the best way to protect users.”

Acinq software developer Bastien Teinturier image via Twitter