Project

Summary

In the OWPIdentity contract, essential functions such as mint, mintBatch, burn, setURI, and others are missing event emissions. This omission reduces the traceability of key operations, hindering effective monitoring and analysis by developers, auditors, and external applications that rely on these events for maintaining logs and verifying contract behavior off-chain.

Vulnerability Details

The OWPIdentity contract implements several functions that are critical to contract operation and transparency. Specifically, functions including setURI, mint, mintBatch, burn, burnBatch, and others lack event emissions. When functions execute without emitting events, it limits visibility into the state changes that occur, as blockchain explorers and external analytics tools rely on these events for recording transactional history. This vulnerability can obscure significant activities, making it difficult to audit and verify contract functionality, particularly around asset minting and burning actions, which are fundamental to the contract's operation.

Without event logging, an attacker or malicious actor with appropriate roles could potentially exploit the contract’s minting or burning functions without triggering any event. This would allow them to modify the contract state without detection, potentially inflating token supplies or silently removing assets. The lack of event emissions significantly impairs the ability to monitor and maintain an accurate, transparent transaction history off-chain.

Link to the Affected Code

• function setURI(string memory newuri) public onlyRole(DEFAULT_ADMIN_ROLE)

  • https://github.com/Cyfrin/2024-11-one-world/blob/1e872c7ab393c380010a507398d4b4caca1ae32b/contracts/OWPIdentity.sol#L23-L25

• function mint(address account, uint256 id, uint256 amount, bytes memory data) public onlyRole(MINTER_ROLE)

  • https://github.com/Cyfrin/2024-11-one-world/blob/1e872c7ab393c380010a507398d4b4caca1ae32b/contracts/OWPIdentity.sol#L31-L36

• function burn(address account, uint256 id, uint256 amount) public override onlyRole(MINTER_ROLE)

  • https://github.com/Cyfrin/2024-11-one-world/blob/1e872c7ab393c380010a507398d4b4caca1ae32b/contracts/OWPIdentity.sol#L45-L50

Impact

Inability to effectively track on-chain transactions and activity related to contract functions off-chain. The likelihood of exploit is moderate, given that an attacker would need role-based permissions. However, due to the inability to monitor these functions externally, the chance of unauthorized actions occurring without detection is considerably heightened.

The absence of events can have severe implications for transaction integrity and transparency:

• Obscured Activity: Key actions like minting, burning, and updating contract states will not be easily visible to auditors and external tracking services.

• Increased Exploit Risk: If an attacker with the necessary role accesses the mint or burn functions, they could engage in unauthorized asset manipulation without detection, leading to potential loss or dilution of assets for users.

• Reduced Accountability: Without event logs, tracing the origin and nature of on-chain changes becomes labor-intensive, impacting security audits and making accountability difficult.

Proof of Concept

Consider the following scenario:

1. A user with the MINTER_ROLE mints additional tokens using the mint function without an event log.

2. The increased token supply, while visible in the on-chain state, will not trigger any off-chain alert or event-based monitoring, enabling stealthy, potentially unauthorized token minting.

Tools Used

Manual Review

Recommendations

Emit events in all functions where state-changing operations are performed. For instance, adding event emissions like Mint, Burn, and URISet can significantly enhance contract transparency. Ensure important fields, especially addresses, are indexed in each event to facilitate efficient querying and filtering of events.

Example:

Adding these event logs will enable the contract to interface seamlessly with off-chain tracking systems and maintain integrity in reporting state changes across the Web3 ecosystem.