Back to Blog

Akutar NFT 损失 3400 万美元

Code Auditing
April 23, 2022
2 min read

我们在 @AkuDreams 合约中发现了两个严重逻辑漏洞: https://etherscan.io/address/0xf42c318dbfbaab0eee040279c6a2588fa01a961d

第一个漏洞可能导致拒绝服务 (DoS) 攻击,第二个漏洞将导致项目资金(超过 3400 万美元)被永远锁定。

漏洞 I

第一个漏洞存在于 processRefunds 函数中。该函数包含一个循环,用于退还每个竞拍用户的资金。然而,竞拍者可能是一个恶意合约,会回滚交易。这可能导致 processRefunds 函数调用回滚,所有用户的退款都将失败。幸运的是,此漏洞尚未被利用。

我们建议合约可以采取以下措施进行退款:

  • 确保只有 EOA(外部所有者账户)可以竞拍
  • 使用 ERC20 代币,例如 WETH,而不是 ETH
  • 提供一个允许用户自行领取退款的函数

漏洞 II

第二个漏洞是一个软件 bug。在 claimProjectFunds 函数中,项目所有者可以提取合约中的 Ether。然而,require(refundProgress >= totalBids, "Refunds not yet processed"); 这个 require 语句存在 bug,它应该将 refundProgress_bidIndex 进行比较,而不是 totalBids。由于这个漏洞,条件永远无法满足,合约中的 Ether(11,539.5 Ether)可能会永远被锁定。

总结

我们再次感到惊讶(继昨天的 NBA NFT 事件之后),一个备受瞩目的项目怎么会忽视基本的软件安全实践。至少,项目应该编写足够的测试用例。不幸的是,我们怀疑项目方可能因为太忙而未能编写测试用例,最终损失了 3400 美元。

关于 BlockSec

BlockSec 是一家开创性的区块链安全公司,由一群全球知名的安全专家于 2021 年创立。公司致力于提升新兴 Web3 世界的安全性和可用性,以促进其大规模采用。为此,BlockSec 提供智能合约和 EVM 链安全审计服务,Phalcon 平台用于安全开发和主动阻止威胁,MetaSleuth 平台用于资金追踪和调查,以及 MetaDock 扩展,供 Web3 构建者在加密世界中高效冲浪。

截至目前,公司已为 MetaMask、Uniswap Foundation、Compound、Forta 和 PancakeSwap 等 300 多家知名客户提供服务,并通过两轮融资从 Matrix Partners、Vitalbridge Capital 和 Fenbushi Capital 等知名投资者那里获得了数千万美元的投资。

官方网站:https://blocksec.com/

官方推特账号:https://twitter.com/BlockSecTeam

Sign up for the latest updates
The Decentralization Dilemma: Cascading Risk and Emergency Power in the KelpDAO Crisis
Security Insights

The Decentralization Dilemma: Cascading Risk and Emergency Power in the KelpDAO Crisis

This BlockSec deep-dive analyzes the KelpDAO $290M rsETH cross-chain bridge exploit (April 18, 2026), attributed to the Lazarus Group, tracing a causal chain across three layers: how a single-point DVN dependency enabled the attack, how DeFi composability cascaded the damage through Aave V3 lending markets to freeze WETH liquidity exceeding $6.7B across Ethereum, Arbitrum, Base, Mantle, and Linea, and how the crisis forced decentralized governance to exercise centralized emergency powers. The article examines three parameters that shaped the cascade's severity (LTV, pool depth, and cross-chain deployment count) and provides an exclusive technical breakdown of Arbitrum Security Council's forced state transition, an atomic contract upgrade that moved 30,766 ETH without the holder's signature.

Weekly Web3 Security Incident Roundup | Apr 13 – Apr 19, 2026
Security Insights

Weekly Web3 Security Incident Roundup | Apr 13 – Apr 19, 2026

This BlockSec weekly security report covers four attack incidents detected between April 13 and April 19, 2026, across multiple chains such as Ethereum, Unichain, Arbitrum, and NEAR, with total estimated losses of approximately $310M. The highlighted incident is the $290M KelpDAO rsETH bridge exploit, where an attacker poisoned the RPC infrastructure of the sole LayerZero DVN to fabricate a cross-chain message, triggering a cascading WETH freeze across five chains and an Arbitrum Security Council forced state transition that raises questions about the actual trust boundaries of decentralized systems. Other incidents include a $242K MMR proof forgery on Hyperbridge, a $1.5M signed integer abuse on Dango, and an $18.4M circular swap path exploit on Rhea Finance's Burrowland protocol.

Weekly Web3 Security Incident Roundup | Apr 6 – Apr 12, 2026
Security Insights

Weekly Web3 Security Incident Roundup | Apr 6 – Apr 12, 2026

This BlockSec weekly security report covers four DeFi attack incidents detected between April 6 and April 12, 2026, across Linea, BNB Chain, Arbitrum, Optimism, Avalanche, and Base, with total estimated losses of approximately $928.6K. Notable incidents include a $517K approval-related exploit where a user mistakenly approved a permissionless SquidMulticall contract enabling arbitrary external calls, a $193K business logic flaw in the HB token's reward-settlement logic that allowed direct AMM reserve manipulation, a $165.6K exploit in Denaria's perpetual DEX caused by a rounding asymmetry compounded with an unsafe cast, and a $53K access control issue in XBITVault caused by an initialization-dependent check that failed open. The report provides detailed vulnerability analysis and attack transaction breakdowns for each incident.

Best Security Auditor for Web3

Validate design, code, and business logic before launch. Aligned with the highest industry security standards.

BlockSec Audit