Aave Faces Potential Losses of Up to $230 Million Following Kelp DAO Bridge Exploit

A devastating bridge exploit involving Kelp DAO and LayerZero has put lending protocol Aave at risk of losing up to $230 million, contingent on the resolution of the situation. According to a report published by Aave Labs and LlamaRisk on the Aave governance forum, the incident revolves around rsETH, a liquid restaking token issued by KelpDAO, which relies on a bridge mechanism to transfer tokens between blockchains. An attacker manipulated this setup by creating a forged transfer message, prompting the system to approve a transfer without removing the tokens from the sending chain, effectively creating new tokens without backing. This resulted in the release of 116,500 rsETH from the Ethereum-side bridge. Rather than selling the assets, the attacker utilized 89,567 rsETH as collateral to borrow approximately $190 million in ETH and related assets across Ethereum and Arbitrum, leaving Aave vulnerable to collateral with potentially significant impairment. In response, Aave Labs promptly contained the risk by freezing rsETH markets, setting loan-to-value ratios to zero, and halting new borrowing against the asset. The outcome now largely depends on how Kelp handles the shortfall. If losses are spread across all rsETH holders, the token would experience an estimated 15% depegging, resulting in around $124 million in bad debt for Aave. Conversely, if losses are isolated to Layer 2 networks, the impact would be more severe, with bad debt rising to roughly $230 million, primarily affecting networks like Arbitrum and Mantle. The exploit stemmed from weaknesses in Kelp's verification of cross-chain messages using LayerZero, allowing the attacker to manipulate the process and extract value from the system. Although LayerZero itself was not directly hacked, its messaging layer exposed flawed assumptions in Kelp's validation of cross-chain data. The incident has raised concerns about positions on Aave being backed by mispriced or insufficiently backed collateral, increasing the risk of undercollateralized loans. In response, users have moved to reduce their exposure, resulting in the withdrawal of around $6 billion in total value locked from Aave. The episode has highlighted Aave's indirect exposure to external systems, with increased collateral risk, pressure on lending positions, and a decline in deposits as users reassess the safety of interconnected DeFi infrastructure. The report indicates that the DAO treasury holds approximately $181 million in assets, with discussions underway to address potential losses. However, Kelp has yet to outline its plan for allocating losses, leaving Aave's ultimate exposure uncertain as the situation continues to unfold.