Symbiosis Cross-Chain Bridge Attacked for 46 Billion Fake Bitcoin Tokens

A recent attack on the Symbiosis cross-chain bridge resulted in the minting of approximately 46.1 billion synthetic Bitcoin tokens, worth about $46.1 billion, from an initial deposit worth just 25 cents.

The attacker exploited two software flaws in the platform to generate these tokens, which are meant to represent actual Bitcoin held by the system but had no real backing.

The attack occurred on September 11, and the attacker processed 12 fraudulent transactions across BNB Chain, Ethereum, and Rootstock in roughly four minutes.

The Symbiosis team attributed the breach to a pair of separate coding errors that compounded each other, allowing the attacker to appear simultaneously as an approved depositor and a bridge administrator.