long video : duration: 50:42 mins Uniswap v4 Hooks & Fuzzing Audit (Status: 12/22/25) Hooks
Architecture in v4: Hooks allow for custom logic in pools. The risk
lies in manipulating the PoolManager. If security fails, an attacker
can divert fees or lock up liquidity. Fuzzing with Foundry: The
Foundry tool is the standard for unit and fuzzing tests. It generates
thousands of random inputs to test functions like beforeSwap, exposing
rounding errors. Invariants in Foundry: In Foundry, invariant
testing (invariant_) is vital for hooks. It ensures that, no matter the
sequence of transactions, certain rules (such as the pool balance) are
never broken. Echidna for Deep Fuzzing: While Foundry focuses on
isolated transactions, Echidna explores complex contract states through
grammatical properties, ideal for finding multi-step logic bugs. Access
Control Flaws: The video exemplifies how flaws in the owner() function
allow attackers to hijack contracts. In hooks, this can lead to
malicious alteration of fee parameters in real time. Pause
Vulnerability: The speaker demonstrates that hooks with poorly
protected pause functionality can be used to freeze user liquidity on
Uniswap v4. Transient Accounting (EIP-1153): In December 2025, hook
audits focus on the correct use of transient storage. Foundry should be
used to ensure that the state is cleared after each swap. Static vs.
Manual Analysis: The video reinforces that Slither helps, but manual
auditing with markings (Audit: Issue) is indispensable for
understanding the economic integration between the hook and the pool. Fee
Fuzzing: Echidna is superior for testing whether the hook's fee
distribution logic can be exploited via price manipulation (Sandwich
Attacks). Conclusion for Developers: Security in 2025 requires the
use of Foundry for full code coverage and tools like Echidna to
validate the protocol's economic resilience.
Here's
a list of 10 specific classes of flaws that Foundry can detect in smart
contracts (including hook logic like in Uniswap v4) when you write
proper tests — each item with a helpful mitigation/detection link
focused on Foundry/fuzz/invariant testing: 1-Violation of Liquidity Invariants
What it detects: situations where the expected sum of reserves is broken after arbitrary operations. Docs.foundry-Invariant Testing (Forge) 2-Inconsistencies in Token Storage
What it detects:Situations where the sum of users' balances does not match
the totalSupply, or where tokens are improperly created or destroyed
without correctly reflecting the overall state of the contract. Zepelin-Secure development of smart contracts 3-Errors in Price Calculations
What it detects: Incorrect price calculation based on external inputs. Docs.foundry-Cobre como testar funções matemáticas com inputs aleatórios. 4-Logical Overflow/Underflow (Property Violations)
What it detects: Mathematical operations breaking expected properties. Docs.foundry-Invariant Testing (Para propriedades de estado) 5-Incorrect State Assumptions
What it detects: Logic depending on invalid or uninitialized states (e.g., balance ≠ 0 initially) Fuzzing Testing Network Protocols for Humans
6-Unauthorized Access / Permission Failure
What it detects:Administrative functions accessed by unauthorized users Inspector-forge 7-Dangerous Call Sequences (Stateful Bugs)
What it detects:Bugs become visible after specific sequences of calls. Reentrancy-chamadas reentrantes para uma função.
8-Violation of Hook Properties V4
What it detects:Breaks price invariants - The asset price after
transactions does not accurately reflect the supply/demand relationship.
Violates liquidity properties - The total value of the pool is not preserved or liquidity becomes inconsistent.
Creates unintentional arbitrage - Allows for risk-free value extraction. Uniswap V4 Hooks Audit: Risks, Exploits, and Secure Implementation
9-Calculating Fees with Incorrect Input
What it detects: Incorrectly applied rates under extreme inputs. Smart Contract Security
10-Pool State Manipulation (Simulated Front-Running)
What it detects: Inconsistent states when many operations are performed sequentially. Market Manipulation vs. Oracle Exploits