Gelato Hack

TOTAL LOST —
Other

Summarize with AI

ChatGPT Perplexity Claude Grok
Affected Chain 2021 Incident surface
Recovered - No recovery reported
Same Technique 415 Total incidents
Protocol Type Exploit/Other Target category

Incident Overview

The transaction behind the exploit:

https://etherscan.io/tx/0x90a5d10c…46c303

The bug in GUniRouter02 within the rebalanceAndAddLiquidity() function was able to be exploited to transfer funds from users' wallets who have previously approved GUniRouter02 for spending their tokens.

Tokens, which were mostly affected: DAI, USDC, FEI, agEUR, FRAX, WETH, ENS, ETH2x-FLI, G-UNI DAI/USDC, and POP.

The root issue: rebalanceAndAddLiquidity() can be invoked with custom _swapAction and _swapDatas parameters. Given the fact that users have given infinite allowances for the router contract, the possible exploiter could drain users' funds from their wallets.

The project team executed a successful whitehat hack which secured around $26M of user funds.

Incident Report

Protocol / Project Gelato
Date of Incident
Attack Technique Other
Classification Exchange (DEX)
Primary Source View Post-Mortem #1 View Post-Mortem #2

Protocol Information

Protocol Type Exploit/Other
Official Website www.gelato.network/
Protocol Twitter/X @gelatonetwork
Team Anonymous
Source Code Unverified

What the Attacker Needed to Succeed

Understanding the prerequisites for this type of attack helps auditors identify protocols that are most at risk and helps developers build better defenses.

Technical Knowledge Deep understanding of other and Solidity and EVM internals
Capital Required Seed capital to cover gas and initial position setup
On-Chain Access Ability to interact with smart contracts and deploy a custom exploit contract
Protocol Analysis Identification of the exploitable vulnerability in Gelato's contract logic - root cause: exchange (dex)
Execution Speed Precise transaction ordering and timing to exploit the vulnerability within a single atomic block
Obfuscation Plan A strategy to launder and move stolen funds - typically through mixers, cross-chain bridges, or decentralized DEX swaps to resist tracing

What Auditors Should Check

Could this have been caught in audit? Likely — with a thorough Other audit checklist and test coverage

If you're auditing a protocol with similar architecture to Gelato, these are the critical security checks that could have prevented this incident (December 2021).

  • Verify all logic paths related to Other are guarded by proper access controls and input validation
  • Review privileged functions (owner, admin, governance) for potential abuse vectors - centralization risks should be documented and bounded with timelocks or multi-sigs

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