Vulnerabilities

Donation Attack

A donation attack manipulates protocol accounting by transferring tokens directly to a contract without using the intended deposit path.

A donation attack changes a contract's balance to trick its accounting.

Donation Attack Explained in Detail

A donation attack sends tokens directly to a contract to change a balance the protocol uses for accounting. The attacker does not mint shares or go through the normal deposit flow.

If the protocol treats raw balanceOf(address(this)) as managed assets, the donation can distort exchange rates, collateral values, or reward math.

Smart contract example

uint256 assets = token.balanceOf(address(this));

This value can include unsolicited transfers.

Donation Attack in Auditing

Donation attacks are simple and often overlooked. They can break vault share math, lending collateral values, LP accounting, or reward distribution.

Auditors check whether the protocol can distinguish intentional deposits from raw token balance changes.

Red flags in code

  • Raw token balance is treated as authoritative assets.

  • Share price changes after direct token transfers.

  • Empty or low-supply vault math is unprotected.

  • Rebasing or fee-on-transfer tokens are accepted without special handling.

  • External protocols trust the manipulated share price.

How to test or review it

  • Transfer tokens directly to the contract before deposit, withdraw, borrow, or redeem.

  • Compare internal accounting with token balance.

  • Test empty, dust, and low-liquidity states.

  • Fuzz donation size and timing.

  • Check whether donations can create bad debt or unfair share minting.

ERC4626 Inflation Attack

An ERC4626 inflation attack manipulates an empty or low-supply vault's asset-to-share rate so a victim receives too few shares.

Share Price Manipulation

Share price manipulation changes the calculated value of vault, pool, or receipt-token shares to exploit deposits, withdrawals, collateral, or rewards.

ERC-4626 Vaults

ERC-4626 is the tokenized vault standard where users deposit an asset and receive vault shares that represent a claim on the vault's assets.

Practice this in real audit scenarios

Definitions help, but auditors need reps. SCH turns concepts like Donation Attack into exploit labs, code review habits, and report-writing practice.

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Sources