Aave Faces $6 Billion Deposit Exodus After Kelp Hack Exposes DeFi Lender's Structural Vulnerabilities

Aave has witnessed a staggering $6.6 billion exit, not due to a direct hack, but as a result of a structural risk exposure. The protocol's total value locked plummeted from $26.4 billion on April 18 to approximately $20 billion by Sunday morning, according to DefiLlama. The AAVE token suffered a 16% decline to $92, while daily fees surged to $1.99 million amidst a wave of liquidations over the weekend. Depositors are fleeing as Aave grapples with a liability it did not create. Attackers drained 116,500 rsETH from Kelp's bridge on Saturday, utilizing the stolen tokens as collateral on Aave V3 to borrow wrapped ether. On-chain trackers estimate the Aave-specific borrow to be around $196 million, with total positions across Aave, Compound, and Euler nearing $236 million. Aave, the largest DeFi lending protocol, allows users to deposit cryptocurrency to earn yield, while others borrow against collateral. Kelp, a liquid restaking protocol, takes already-staked ether on Ethereum and channels it through EigenLayer, issuing a receipt token, rsETH, in exchange. This rsETH is what users trade and, crucially, what some users posted as collateral on Aave to borrow against. On Saturday, attackers deceived Kelp's cross-chain bridge into releasing 116,500 rsETH, worth around $292 million, to a controlled address. They then deposited the stolen rsETH onto Aave V3 as collateral and borrowed wrapped ether against it. Aave initially stated that the Umbrella reserve would cover any deficit, but by Saturday afternoon, the language had shifted to exploring paths to offset the deficit. The concentration of damage is attributed to Aave's loan book, which spans 22 chains, with Ethereum alone holding $14.24 billion of the $17.82 billion in outstanding borrows. WETH accounts for 39.49% of all loans on the protocol, making the attack particularly impactful. Stani Kulechov, Aave's founder, emphasized that the exploit was external and the protocol's contracts were not compromised. However, Aave accepted a liquid restaking token as collateral, and the token's backing vanished on a bridge Aave does not control, leaving depositors vulnerable to losses. Liquid restaking tokens were whitelisted across major lending protocols due to their yield and growing share of Ethereum's locked value. Risk models priced them as if they would maintain their peg under normal conditions, but failed to account for a scenario where the collateral's value drops to zero due to a bridge exploit on an unrelated chain. The token price now reflects concerns over whether the Umbrella reserve is sufficient to cover the resulting hole and whether stkAAVE holders backing the reserve will absorb the loss.