XRP Bridge Drained of 200,000 XRP in Fake Deposit Exploit

An attacker drained nearly 200,000 XRP from a crosschain bridge connecting the XRP Ledger to the Coreum blockchain on August 9, exploiting a software vulnerability that allowed fraudulent deposit records to trigger real withdrawals. The incident, which unfolded over approximately 97 minutes, resulted in the theft of about 199,916 XRP, leaving the bridge with a balance of just 493.5 XRP. The bridge has since been halted, and the operator, tx, has filed a report with the FBI's Internet Crime Complaint Center.

The exploit targeted the bridge's deposit verification system. Blockchain bridges typically function by locking assets in a reserve on one chain and issuing equivalent wrapped tokens on another. The attacker discovered a way to obtain withdrawal vouchers without making a real deposit. The bridge's relayer software, which monitors both blockchains and validates transfers, checked whether a payment succeeded and read attached memo fields but failed to confirm whether the payment was actually sent to the authorized bridge address.

The perpetrator executed peer-to-peer wallet transfers containing memos crafted to mimic legitimate bridge deposits. The relayer software interpreted...