How much was lost in the Vesper Finance hack?

The Vesper Finance hack resulted in $3.4M in losses on November 03, 2021.

What attack technique was used in the Vesper Finance exploit?

The Vesper Finance exploit utilized Oracle Manipulation / Other. Understanding this attack vector is critical for smart contract auditors and developers building secure DeFi protocols.

How can developers prevent similar smart contract attacks?

Preventing smart contract hacks requires a combination of secure coding practices, thorough security audits, and understanding common attack vectors like reentrancy, oracle manipulation, and access control flaws. Smart Contract Hacking (SCH) provides hands-on training to help developers and auditors identify and prevent vulnerabilities before deployment.

Vesper Finance Hack

TOTAL LOST $3.4M

Medium Nov 03, 2021 Oracle Manipulation / Other ethereum

Affected Chain ethereum Incident surface

Recovered - No recovery reported

All-Time Rank #528 By amount stolen

Auditors 1 Prior security audit

Incident Overview

The attacker's address:

https://etherscan.io/address/0xa3f447fe…619264

The attacker:

- received ~100 ETH from Tornado Cash to ensure his privacy:

https://etherscan.io/tx/0x1423391a…5f8cba

- swapped 56.81 ETH to 254,783 USDC

-swapped 232,509 USDC to 222,403 VUSD on the Uniswap v3

- added liquidity into "infinity" price range using 0 VUSD and 0.1 USDC:

https://etherscan.io/tx/0x89d0ae4d…ecf4c5

- deposited VUSD as collateral into the Vesper Rari Fuse pool #23 and was able to borrow all available assets:

https://ethtx.info/mainnet/0x8527fea5…af8092/

- The Rari lending market received the VUSD price using Rari's price oracle:

https://etherscan.io/address/0xb3c8ee73…36d8fb

, and valued VUSD collateral at a price of “infinity”

- swapped stolen assets on ETH:

https://etherscan.io/tx/0x70d6ff9f…19bc7d

- deposited ETH into Tornado Cash mixer:

https://bloxy.info/txs/calls_from/0xa3f447fe…619264?signature_id=994162&smart_contract_address_bin=0x722122df…5b6967

This is classified as a Oracle Manipulation & Price Manipulation . Compare similar hacks →

Incident Report

Protocol / Project Vesper Finance

Date of Incident November 03, 2021

Affected Chain(s) ethereum

Attack Technique Oracle Manipulation / Other

Classification Protocol Logic / Yield Aggregator

Primary Source View Post-Mortem

Protocol Information

Protocol Type Dexs

Affected Token VUSD

Smart Contract Language Solidity

Official Website vesper.finance/

Protocol Twitter/X @VesperFi

Market Context at Time of Hack

Token Categories

Avalanche Ecosystem

Protocol Links

GitHub Discord

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 oracle manipulation / other and Solidity and EVM internals

Capital Required Seed capital to cover gas and initial position setup

On-Chain Access Ability to interact with ethereum smart contracts and deploy a custom exploit contract

Protocol Analysis Identification of the exploitable vulnerability in Vesper Finance's contract logic - root cause: protocol logic / yield aggregator

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? Yes — skilled auditors routinely flag Oracle Manipulation / Other vulnerabilities in code review

Audited by Audit Report 1 — still lost $3.4M. Prior audits don't guarantee safety, especially after post-audit code changes.

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

Verify all logic paths related to Oracle Manipulation / Other are guarded by proper access controls and input validation - see the Oracle Manipulation & Price Manipulation attack class for patterns
Audit oracle price feeds for manipulation risks - ensure time-weighted average prices (TWAPs) or multi-source aggregators are used, not spot prices
Review privileged functions (owner, admin, governance) for potential abuse vectors - centralization risks should be documented and bounded with timelocks or multi-sigs

Master these auditing techniques with hands-on labs and real exploit scenarios in the Smart Contract Hacking course.

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Security Audit History

Audit Report 1 Report

Related Attack Classes

The technique used in this hack maps to these vulnerability classes in our security curriculum:

See all Oracle Manipulation & Price Manipulation examples →

Oracle Manipulation & Price Manipulation

Sources & References

01
Source 1 https://x.com/VesperFi/status/1455567032536248324
02
Reference https://medium.com/vesperfinance/on-the-vesper-lend-beta-rari-fu…
03
Reference https://twitter.com/mudit__gupta/status/1455627465678749696?s=21
04
Reference https://twitter.com/RariCapital/status/1455569653820973057

Threat Assessment

Severity Level

MEDIUM

Attack Vector Oracle Manipulation / Other
Root Cause Protocol Logic / Yield Aggregator
Year 2021

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