NEAR Intents Releases Post-Mortem Report, $3.8M Vulnerability Stemmed from Deposit Notification Flaw

Cross-chain exchange protocol NEAR Intents released a post-mortem report attributing a $3.8 million vulnerability to a flaw in its deposit notification feature. The protocol's public settlement contract deployed on NEAR maintains an internal ledger of deposited tokens, while withdrawals transfer tokens out via cross-chain bridges. The report, released by NEAR Intents General Manager Alex Shevchenko on October 16, stated that the attacker extracted $3.8 million before the protocol was halted on October 1, and returned all funds within 36 hours of detection, with all affected users fully compensated. The report showed that the feature notifies third-party contracts when tokens are deposited. The attacker created a contract that deliberately caused notifications to fail, leading the token contract to refund the deposit while NEAR Intents still retained the corresponding ledger credit. Across 23 failed deposit transactions, the attacker accumulated $3.8 million in unsupported balances, which the report termed "ghost funds," subsequently using them to withdraw real tokens and transferring them to other chains via Omni infrastructure. Shevchenko stated this was a vulnerability in the NEAR Intents contract, not in the Omni infrastructure. Withdrawals occurred between September 29 and October 1. The settlement contract was paused and reopened on October 1, with affected routes gradually restored thereafter, and contract-side deposits resumed on October 2. The report noted the vulnerability went undetected because monitoring only compared raw chain assets against total token balances on the NEAR side, without comparing the sum of user internal balances against tokens actually held by the contract; the team has added this check and will automatically pause the contract when balances are inconsistent. A fix for the October vulnerability was deployed on October 2, but a separate critical vulnerability report on the same feature prompted its complete removal on October 7, with the researcher involved receiving a $300,000 reward.