Balancer V1 Pool Drains $234K in Exploit Linked to Calculation Error

BitcoinWorld Balancer V1 Pool Drains $234K in Exploit Linked to Calculation Error Balancer, a prominent decentralized finance (DeFi) protocol, has suffered a security breach resulting in the loss of approximately $234,000 from a Balancer V1 BPool.

The exploit, detailed by blockchain security firm SlowMist, targeted a vulnerability stemming from a calculation error in the pool’s logic, allowing the attacker to drain assets through a series of manipulated swaps.

How the Attack Unfolded According to SlowMist’s analysis, the attacker exploited a flaw in the `joinswapPoolAmountOut` function, which calculates the amount of tokens required to mint pool tokens.

By repeatedly using public swaps, the attacker reduced the pool’s WBTC balance to near zero. Subsequently, they manipulated the function to compute the required WBTC input as roughly one satoshi (the smallest unit of Bitcoin).