bZx Hack

TOTAL LOST $8.1M
Medium Other ethereum

Summarize with AI

ChatGPT Perplexity Claude Grok
Affected Chain ethereum Incident surface
Recovered $8.1M 100.0% returned
All-Time Rank #343 By amount stolen
Auditors 3 Prior security audits

Incident Overview

Quick Summary

bZx's flawed code allowed an attacker to duplicate assets, leading to a loss of approximately $8.1 million.

Details of the Exploit

The bug in bZx's code allowed the attacker to increase their balance of iTokens (interest-bearing tokens of bZx). The attacker was able to mint 219,200 LINK tokens (worth about $2.6 million); 4,503 ETH (~$1.6 million); 1,756,351 USDT (~$1.7 million); 1,412,048 USDC (~$1.4 million) and 667,989 DAI (~$680,000). The total loss amounted to approximately $8.1 million.

bZx has assured that no user funds are at risk as the loss is being covered by its insurance fund.

Incident Report

Protocol / Project bZx
Date of Incident
Affected Chain(s) ethereum
Attack Technique Other
Classification Other
Primary Source View Post-Mortem #1 View Post-Mortem #2 View Post-Mortem #3

Protocol Information

Protocol Type Exploit/Other
Affected Token BZRX
Official Website bzx.network/
Protocol Twitter/X @bzxHQ
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 ethereum smart contracts and deploy a custom exploit contract
Protocol Analysis Identification of the exploitable vulnerability in bZx's contract logic - root cause: other
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
Audited by Certik, DeFi Safety, ZK Labs — still lost $8.1M. Prior audits don't guarantee safety, especially after post-audit code changes.

If you're auditing a protocol with similar architecture to bZx, these are the critical security checks that could have prevented this incident (September 2020).

  • 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

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

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Funds Recovery

100.0%

Recovered

$8.1M

Net Loss

0

Security Audit History

Sources & References

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