Ignored slippage messages, lost $50m in just one "approve"

[rat03gopoh]

In short, a trader lost more than $50m after trading aEthUSDT to aEthAAVE on a DEX via mobile. Well, you heard that right, $50m in mobile wallets. The trader actually received warnings about high slippage costs that were ignored. I don't know if he realized he had entered that amount manually or just clicked "max".

The swap process (backend) is a bit complicated with such a large amount: https://etherscan.io/address/0x98b9d979c33dd7284c854909bcc09b51fbf97ac8#tokentxns

• aEthUSDT to USDT: The solver burned 50.43M aEthUSDT via Aave V3, withdrawing 50.43M USDT.
• USDT to WETH via Uniswap V3: 50.43M USDT went into the Uniswap V3 USDT/WETH pool and came out as 17,958 WETH. At $2,050/ETH, $50.4M should yield roughly 24,600 WETH. That's roughly $13.6 million lost to slippage at the Uniswap step alone.
• WETH to AAVE via SushiSwap: Here's where it gets catastrophic. The SushiSwap AAVE/WETH pool currently has only about $73,000 in total liquidity. The solver pushed 17,958 WETH through this tiny pool and got back only 331 AAVE, worth $36,400. That's effectively 99.9% slippage.
• AAVE to aEthAAVE via Aave deposit: 331 AAVE was deposited back into Aave V3, minting 327 aEthAAVE, which was delivered to the trader.

https://thedefiant.io/news/defi/whale-swaps-usd50-million-in-stablecoins-for-just-usd36-000-of-aave

perhaps this is why the slippage warning does not represent the information accurately.

[TastyChillySauce00]

This is the weakness of current swap router contract, their routing is so confusing and there is no way to determine the real output we gonna get and instead we're only getting minOut or max slippage as a guardrail.

There are simply tons of ways we can lose our money using these dex from malicious delegation, unlimited approval, fake token, low liquidity, to getting front ran by a freaking mev bots .