An attacker drained approximately 1,783 wstETH, worth roughly $6 million, from a vault on the Base network early Friday morning by exploiting a whitelist permission to add a malicious contract.
The exploit unfolded across six transactions in 25 minutes starting at 08:55 UTC. The attacker began with a test transfer of 1 wstETH, then withdrew 100, 500, 500, 500, and 182.067 wstETH in rapid succession between 09:08 and 09:12 UTC. Security platforms Blockaid flagged the activity at 09:20 UTC while the drain was still in progress. PeckShield later quantified the total loss at 1,783.067 wstETH, leaving only 0.0007 wstETH in the vault.
The vault's own access controls enabled the attack. The attacker added a new contract to the vault's whitelist, borrowed aBaswstETH, an Aave interest-bearing token, through the compromised vault, moved the aTokens off-chain, and redeemed them into clean wstETH. The attacker added the contract to the whitelist without identified authorization. The vault owner has not made a public statement.
At 09:27 UTC, the attacker routed 1 wstETH through Lido's Base-to-Ethereum bridge, a path that carries a seven-day settlement window. The full 1,783.067 wstETH remains on Base and visible on-chain; it has not yet crossed the bridge. The funds are visible at address 0x0B51…B034.
Whitelisting exploits have emerged as a recurring vulnerability vector in decentralized finance. In July 2023, the Curve Finance platform lost $50 million after an attacker exploited a similarly permissioned contract whitelist. Aave's integration with vault protocols creates a straightforward path to cash-out once an attacker gains contract approval authority. Base vaults rely on multi-signature control schemes, the unidentified vault operator's setup included seven signers, yet a single whitelisted contract can bypass those governance layers if the approval mechanism itself lacks proper validation.
The delay imposed by Lido's bridge settlement creates a window for the vault operator or security researchers to trace funds, pursue on-chain recovery mechanisms, or coordinate with exchanges and bridge validators. Whether any party holds the authority to reverse the redemption or freeze the bridging depends on the vault's own charter and whether its operators can escalate to Aave governance or Lido's operations team.
The attacker executed the full extraction in under 25 minutes and initiated the bridge crossing within 35 minutes of the first withdrawal. Whitelist additions do not typically occur without explicit governance or admin action. If the vault owner cannot identify who triggered the whitelist change, recovery hinges on whether the bridge window allows intervention before tokens settle on Ethereum.
