SWAP:BlockSec DeFi攻擊分析系列之二傾囊相送：Sushiswap手續費被盜-ODAILY

去中心化金融(DeFi)作為區塊鏈生態當紅項目形態，其安全尤為重要。從去年至今，發生了幾十起安全事件

BlockSec作為長期關注DeFi安全的研究團隊(https://blocksecteam

_toWETH函數：

function_toWETH(addresstoken)internalreturns(uint256){//對于SUSHI，直接Sushimaker全部SUSHI轉給Barif(token==sushi){uintamount=IERC20(token)

//對于WETH，直接將全部WETH轉給WETH/SUSHI交易對，swap出相應的SUSHIif(token==weth){uintamount=IERC20(token)

//獲取token/WETH的交易對地址IUniswapV2Pairpair=IUniswapV2Pair(factory

//計算可以換出的WETH數量：amount0out，amount1Out//獲得交易對中兩種資產的數量(uintreserve0,uintreserve1,)=pair

看出什么亮點了嗎？

SushiMaker里的轉賬邏輯都是：transfer(balanceOf(this))

我們可以分兩個階段來看convert的調用過程：第一個階段：在convert函數中SushiMaker擁有的是SLP，它通過burnbalanceOf(this)實現將全部SLP換成兩個底層代幣第二個階段：SushiMaker獲得了burn來的底層代幣，再拿burn得到的token去不同的交易池換wETH

你發現哪里有問題了嗎？我們來看第二階段的代碼_toWETH：注意兌換的邏輯為：

uintamount=IERC20(token)

,"profit":"0

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元宇宙概念股Roblox第一季度營收5.37億美元不及預期，凈虧損1.6億美元:5月11日消息，有“元宇宙第一股”之稱的電子游戲平臺Roblox發布2022年第一季度財務報道，數據顯示，包括營收、遞延性營收和其他調整金額在內的預訂量同比下降3%，至6.312億美元。Roblox第一季度營收同比增長39%至5.371億美元，不及分析師普遍預期的6.46億美元，該公司公布其凈虧損從1.342億美元擴大至1.602億美元。在最新業績公布之后，Roblox股價在美股盤后一度跌超12%。（智通財經網）[2022/5/11 3:06:35]

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,{"YFI/WETH":{"0x1b0eb70bc4d2407745df416acf6e2c312d25ee63c7e8e1291545d66e23fbf704":"PreAttack","0x8f6caabd4ecfad30793db76f60a7e28832a18e2bcf006c0ee3652063c7386778":"Convert","0xe6d28052b55ab520a211daebbc67ee3aece6ae356044e9352fc82910214a038a":"Swap"},"profit":"-0

BlockBar獲得2022年LVMH創新獎潛在候選人之一:金色財經消息，近日，LVMH提名奢侈葡萄酒品牌NFT市場BlockBar作為2022年LVMH創新獎的潛在候選人之一。鑒于此，BlockBar將于下個月在巴黎VivaTech的LVMH實驗室展示。活動將持續4天，從6月15日到18日。入圍LVMH 2022創新獎絕非易事。只有21家創新創業公司將有機會與LVMH Lab一起展示。而BlockBar就是其中之一。

活動期間，評審團將選出6家初創公司獲得獎項。在這6家中，只有1家將獲得2022年LVMH創新獎。為了晉級，BlockBar需要在活動期間向LVMH展示其對奢華的愿景。

據BlockBar官網介紹，BlockBar是一個直接提供來自奢侈酒品牌的NFT平臺。每個NFT對應一個物理瓶子。消費者可以將數字版換成實體版。簡單來說，消費者擁有實體瓶，BlockBar為他們存儲，數字版本作為真實性證明、所有權驗證以及實體瓶交付的權利。（nftevening）[2022/5/8 2:58:08]

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,{"USDC/WETH":"Failed"},{"COVER/WETH":"Failed"},{"YAX/WETH":{"0x063bc5df97c0ec87d6c309b54fbc4e3ed13b22f5a115fb1170015e4e9d23cd3d":"PreAttack","0x9537551d0db7ed6ae372c050c73cae1272f4d7e7847ea908d6e4d440809a871f":"Convert","0x9f6bdf1c9065f5f5e5c71f32058093b7ac06e140c3a33db2f21cc8a5ff8a5d21":"SwapExactETHforTokens","0x9281c35277ea6594924600d70b73077a4307973c540edb5b4ed534c7e25f2423":"Approve","0xe2f682d8b4801061d504025f11b3032648a3b94019396f7b12749b162f8404cf":"RemoteLiquidityETH","0xf6ea6c9eb92ca9aed70e8b4b03a6e5565a3a13df71a0aa527fa556077de553bc":"Approve","0xbf19c9a6a4d879467519299100b4f56c4e86369382ba87d90bebf6c1b1893c14":"SwapExactTokensForETH"},"profit":"1

Argo Blockchain 10月份加密貨幣挖礦業務收入和利潤率上漲:倫交所上市比特幣挖礦公司Argo Blockchain發布報告稱，10月份其加密貨幣挖礦業務的收入有所增加，利潤率也有所提高。

該公司10月份收入為120萬英鎊，高于9月份的110萬英鎊，而其月平均挖礦利潤率從37%升至40%。該公司還報告稱，在10月份開采126枚比特幣或比特幣等價物，而9月開采量為127枚，使得今年迄今為止開采的比特幣總量達到2254枚。

Argo表示，截至10月底其持有137 BTC，挖礦能力為16000臺機器。該公司補充說，它已經與比特大陸密切合作，為其表現不佳的T17 Antminer找到解決方案，并已同意淘汰部分礦機。（Proactiveinvestors）[2020/11/5 11:43:41]

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,{"OUSD/WETH":{"0xc4c196e2383e472edf7dee0c93830f20b3314490d9145dfeac936249688a4cd8":"SwapExactETHForTokens","0x975e65569e52644fe7b029ce28fef2c3f07dcb818ea9c9d4b7235ab7c4e11c67":"Approve","0x8c569e7eaa6d7dfc57d5115e628a2b8fc2628837d4e73d6ca85125f639e4f0d0":"AddLiquidityETH","0x0f2ed674f497069878c585297812f036a6dd50060e0685e275092320a3797db0":"Approve","0x483eb12c36b997e9fcb26210e116400f13702db4887b0f4cc3e04fdb8d40c04b":"AddLiquidityETH","0xc18eb762dc3fe84afdc7d2642f380c7f56c5ac18eb9a50103766ba0caa5a6bdf":"Transfer","0x45fd39eef68076c052908c7f8a214cac1cad073f2b5ccf0b919e95670bc801d5":"Convert","0x32beea84a5b4916cd7107adbb8f609071547e78751c360ceee9bff455d3e7660":"SwapExactETHForTokens","0x2eb1802c7771695e6dc0835ed2a0e4d029345f35f1d465b8f15ccae11824da2a":"RemoteLiquidityETH","0x2be981eb82e7577ce43c91718e734cc83e7dd4b384095ea18d62540e53b391bc":"SwapExactTokensForETH","0x584c6f03a2029bc1b262f31016d87156af3c0c773ebad44f6a2b1e63d623ba5d":"SwapExactTokensForETH"},"profit":"0

動態 | BlockRe為其加密保險業務推出新的風險評估工具:加密資產保險公司BlockRe宣布推出一個全面承保和風險評估工具。該工具將有助于在區塊鏈加密資產空間中簽發保單。[2018/11/8]

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,{"LINK/WETH":{"0x62b3ae66524c68ddabd255066807cd7b7f7304e4e8b2da72b9a5e4d8352d35b9":"PreAttack","0xb0f7512a12afabb56b3d69cef4df83add82c81338dc92e059d8ba130ef777a1e":"Convert","0x54570d6f723c3b9f9c6c9e5f7c0357ba50c847b87f17ef5bb517416dcc7f47c3":"Swap"},"profit":"0

,{"RSR/WETH":{"0xa69b5290fe5dd5580e0c738baa47000cf51ed77cc06b8b54a244c7509f8002ad":"PreAttack","0x87a639847c58b6704f28407be39e3ec64b01f005b47753b1a99faf776ea11780":"Convert","0xa458915881d79debafe5f465843931e572321d35bc98ec25db9ecb9f6a3ea6fd":"Swap"},"profit":"0

,{"CORE/WETH":{"0xa01fd6fcfee90a7a2b0a180e7271b9429e9f23cf502ba7966932e5012c1bc9b7":"PreAttack","0x05af95d603cba12d9ca14ce307a973c8875cdcb2e70b07b295440cd2940ea953":"Convert","0x9bb8b7ca5b41c55a8efcdcd49fdec16747ccee0bf33df8e8f4d62eb116142b21":"Swap"},"profit":"0

,{"zLOT/WETH":{"0x0bb5d792a1d1ea598e45997d5dedb4fcf6acafab47afdb45892417cd128cf37f":"PreAttack","0x2550eb33adbe7cfb68cce685363ad2cab90860e5e8a8ed87de1f0a6321e24cf8":"Convert","0x514bd13f68c8afc1f86ea3e74ca5f51724c2736fa327144b7b6aaf7228bd9124":"Swap"},"profit":"0

Blockchain Studios宣布將推出用于可收藏虛擬賽車:今天， Blockchain Studios在2018共識大會上，宣布推出CryptoCarz，并稱CryptoCarz為基于以太坊的最有收藏價值的資產。CryptoCarz是獨一無二的限量版虛擬汽車，可以作為收藏，為快速增長的電子競技市場做準備。[2018/5/16]

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,{"AKRO/WETH":{"0xc38c30660b9c06e9cecc77c9ff0019020eb9c6fa20887dc15b354ed1a50fec26":"PreAttack","0x03b9eb788861e5442c3739738cfa848c73f20871e110c6587609169136c3e772":"Convert","0x88d3a3e31df87329e87fbfc21b9648907365c1e2d5a7a236eae5655c1ba3ad41":"Swap"},"profit":"0

,{"DAI/WETH":{"0x6964f68672edb916ae170254ee48c537cbb64ca0584651d21fd575550559354f":"PreAttack","0x61856228835bfd97dc6b9d7674aaabb577b74fa7d7ff7b7f45454a8d521ff533":"Convert","0x053ebfe8aedd5975137cfa9bf7d7329a2d6413f6d6e364b252f4386222957eed":"Swap"},"profit":"0

,{"YFI/WETH":{"0xf28c246bf1ce25da1811c7c0eb6fefb8587fa2cdafc84cec4e709600429e6e3f":"PreAttack","0xc75a8ca881d4da75774f51006651c9946311d40145ce69d07aee3a85627153d6":"Convert","0x332c7eff23c9022fe6578550a079034cd3356d9f66507d2ec38462169a4b282c":"Swap"},"profit":"0

,{"UBXT/WETH":{"0x635c79a8dca89a3aa95f545e2243a735906c4ff221cfbc160396c150d58ea036":"PreAttack","0x3ffcfc9985622ad7cf0fdc2eb582ad7ce8bf9e9295fd7a4de44354fdd71a688a":"Convert","0x7c6af5ca27ceb04aad514ddcaee8afc6dd4eb79d0816e24b007e7db205e93ce3":"Swap"},"profit":"1

,{"0xMaki":"Iseeu."},{"WBTC/WETH":{"0xa195c9c23a56ca5fa747677c04a2d5a8c513bdfd141e45c20a8c4e091ca73883":"PreAttack","0x136b1d2bf6c51a6ed1fc3f1da7a2783e3835fa78c9149c1c6d2b21e9aad8b05b":"Convert","0x43cde98b0be5932b8dbf709eebd0cbb4738599c9a4f0795ddb52d7d31f293cf4":"Swap"},"profit":"2

,{"USDC/WETH":{"0xfc8196231bfb22ae6fcc9ceb04f9e5e3d647fc9e023870020048be93958218a5":"PreAttack","0xe43fe2eb54c2eefba519a7ff9cf27f84e743961268dfdf9477a47cd2ea467642":"Convert","0x4b0b3b51150b3a270d10f3388ccf12a196a2cada4203e3a2c39af88d5dc04958":"Swap"},"profit":"1

,{"LINK/WETH":{"0x95eea1cedccffc405d0cb9743360712b69a295a66fe0649b5ab1b067869f05fa":"PreAttack","0xf259718ee2f81b543bbfbe2f236cd4235651f8365ec8944741a3c7f3242f06b9":"Convert","0x525929006fc3f089d67b6596f53c5ebe6b82de1f8d3cdeb397f1f55ff4937c47":"Swap"},"profit":"0

后續攻擊者又嘗試攻擊Sushiswap的其他相關仿盤項目，如LuaSwap：

https://etherscan

function_toETH(addresstoken){..

New：0x280ac711bb99dE7C73FB70fb6DE29846D5e4207Ffunctionconvert(addresstoken0,addresstoken1)public{//Atleastwetrytomakefront-runninghardertodo

function_toETH(addresstoken,uintamountIn){...}

可以看到區別在于：代碼第26行_toWETH限制了amount，這樣修改以后就不會將SushiMaker中存的全部SLP都去池中換成wETH，而只是換取burn出的一部分

但是這樣問題就解決了嗎？其實還沒有，時隔兩個月，同樣的地方，Sushiswap又中槍了見：amenda：SushiSwap攻擊事件(2021年1月27號)分析(https://zhuanlan.zhihu.com/p/372058217)

0x3.參考

以小博大，簡述SushiSwap攻擊事件始末：https://www.chainnews.com/zh-hant/articles/726256718885.htm

Astokenpricerisesandreputationmends,Sushiswapfoilsmidnightexploit:https://cointelegraph.com/news/as-token-price-rises-and-reputation-mends-sushiswap-foils-midnight-exploit

AnevolutionofUniswapwithSUSHItokenomics：https://sushichef.medium.com/the-sushiswap-project-dd6eb80c6ba2

一文看懂Uniswap和Sushiswap：https://zhuanlan.zhihu.com/p/226085593

sokdecentralizedexchanges(dex)withautomatedmarketmaker(amm)protocols:https://arxiv.org/abs/2103.12732

AttackingtheDeFiEcosystemwithFlashLoansforFunandProfit:https://arxiv.org/abs/2003.03810

https://www.blocksecteam.com/

contact@blocksecteam.com

Tags：QUOETHSWAPWETQUO幣BAETHCSWAPweth幣價格

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