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hats-finance / Proof-Of-Humanity-V2-0xef0709445d394a22704850c772a28a863bb780b0

Proof of Humanity Protocol v2
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weak randomness #104

Open hats-bug-reporter[bot] opened 2 weeks ago

hats-bug-reporter[bot] commented 2 weeks ago

Github username: -- Twitter username: itsabinashb Submission hash (on-chain): 0x4c2b94e0b6989e3e42945c99ab7783f130af9fd5ce47d617f7e37be04e6461d7 Severity: high

Description: Description\ The use of keccak256 hash functions on predictable values like block.timestamp, block.number, or similar data, including modulo operations on these values, should be avoided for generating randomness, as they are easily predictable and manipulable. The PREVRANDAO opcode also should not be used as a source of randomness. Instead, utilize Chainlink VRF for cryptographically secure and provably random values to ensure protocol integrity.

The severity is high because - Transfer hash must be unique.

Attack Scenario\

Attachments

  1. Proof of Concept (PoC) File https://github.com/hats-finance/Proof-Of-Humanity-V2-0xef0709445d394a22704850c772a28a863bb780b0/blob/07f6529954291f79b3c690881004f306da97759f/contracts/CrossChainProofOfHumanity.sol#L267-L270

  2. Revised Code File (Optional)

clesaege commented 2 weeks ago

The transaction hash just needs to be unique. It doesn't need to be random nor unpredictable.