BNB Smart Chain to hard fork following $100M exploit

A hard fork to the BNB Smart Chain, the blockchain of crypto exchange Binance, will take place as a fix for the exploit that drained the platform of an estimated $100 million on Oct. 6, according to a post on GitHub.

The release for mainnet and testnet is a “temporary urgent patch to mitigate the cross-chain infrastructure between Beacon Chain and Smart Chain”, said the post, aiming to re-enable the cross-chain back.

The BNB hard fork, dubbed Moran, will take place at block height 22,107,423 — estimated to occur on Oct. 12 at 4:00am EST . Changes will include fixing a vulnerability in the iavl hash check, as well as introducing block header in sequence checks.

While the fork does not affect regular users, node operators will have to follow a few steps, such as stopping the actual node if it’s still running, and replacing it with a new binary.

In short, a hard fork is an upgrade meant to improve a blockchain. It’s a permanent divergence from a blockchain’s most recent version, leading to a separation of the chain. As some nodes no longer meet consensus, two versions of the network are run separately. In this way, a fork on the blockchain is created where one path keeps following its current set of rules, whereas the second path follows a new set.

A vulnerability in the cross-chain bridge on BNB Chain caused its pause on Oct. 6, with attackers making off with $100 million in cryptocurrency. The exploit, which was perpetrated on the BSC Token Hub, created “extra BNB”, explained the company.