How a zeroed oracle signature unlocked $9M from Hedera DeFi lender Bonzo Lend
Bonzo Lend, a Hedera-based lending protocol, paused withdrawals and remained under maintenance after an oracle verifier accepted a proof with a zeroed signature and public key. That allowed a wallet to inflate the SAUCE/wHBAR price by about 12 orders of magnitude, then borrow roughly $9.05 million against 250 SAUCE, including about 6.63 million USDC and 34.5 million wrapped HBAR. The flaw came from the verifier passing identity inputs to Hedera’s pairing precompile, which returned true as mathematically expected, but was incorrectly treated as valid committee authorization. Bonzo kept Bonzo Lend and Bonzo Points paused while Bonzo Finance Labs and the Bonzo Finance Foundation worked on recovery. A second wallet borrowed about $1 million and said it was acting as a white-hat responder; Bonzo counted it as recovered, though repayment was not yet final. Supra said it fixed the verifier, but reopening, reimbursement, and withdrawal terms remained undecided.
