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

A devastating bridge exploit targeting Kelp DAO and LayerZero has put lending protocol Aave at risk of incurring losses of up to $230 million, contingent upon the resolution of the situation. According to a report published by Aave Labs and risk provider LlamaRisk on the Aave governance forum, the incident revolves around rsETH, a liquid restaking token issued by KelpDAO. The protocol utilizes a bridge mechanism to transfer rsETH between blockchains, locking tokens on one chain while issuing corresponding tokens on another. An attacker exploited this setup by fabricating a transfer message that appeared legitimate, resulting in the system approving the transfer despite the tokens never being removed from the sending chain. Consequently, new tokens were effectively created without backing, leading to the release of 116,500 rsETH from the Ethereum-side bridge. Instead of selling the assets on the open market, the attacker deposited 89,567 rsETH into Aave as collateral and borrowed approximately $190 million in ETH and related assets across Ethereum and Arbitrum. This has left Aave exposed to collateral with potentially impaired backing. In response to the incident, Aave Labs swiftly took measures to mitigate the risk, freezing rsETH markets across its deployments, 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 approximately $124 million in bad debt for Aave. However, if losses are isolated to Layer 2 networks, the impact would be more severe, with bad debt rising to roughly $230 million and concentrated on networks such as Arbitrum and Mantle. The exploit stemmed from weaknesses in Kelp's cross-chain message verification process using LayerZero. By manipulating this process, the attacker was able to make certain assets appear fully backed when they were not, allowing them to 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 that some positions on Aave were backed by collateral that was mispriced or no longer fully backed, increasing the risk of undercollateralized loans. In response, users have moved to reduce their exposure, with around $6 billion in total value locked withdrawn from Aave following the incident. The episode has highlighted Aave's indirect exposure to external systems, with the impact felt through increased collateral risk, pressure on lending positions, and a sharp decline in deposits as users reassess the safety of interconnected DeFi infrastructure. According to the report, Aave's DAO treasury holds approximately $181 million in assets, and discussions are underway with ecosystem participants to address potential losses. Kelp has not yet outlined its plan for allocating losses, leaving Aave's ultimate exposure uncertain as the situation continues to unfold.