CVE-2018-13521 in PinkyToken
Summary
by MITRE
The mintToken function of a smart contract implementation for PinkyToken, an Ethereum token, has an integer overflow that allows the owner of the contract to set the balance of an arbitrary user to any value.
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Analysis
by VulDB Data Team • 02/27/2020
The vulnerability identified in CVE-2018-13521 represents a critical integer overflow flaw within the mintToken function of the PinkyToken smart contract implementation on the Ethereum blockchain. This vulnerability stems from improper input validation and arithmetic handling within the contract's code, creating a scenario where the contract owner can manipulate user balances arbitrarily. The flaw exists in the token contract's logic that governs the creation and distribution of new tokens, specifically when the mintToken function processes requests to mint new tokens for users.
The technical implementation of this vulnerability manifests through the lack of proper overflow checks in the arithmetic operations performed during token minting. When the mintToken function executes, it likely performs operations such as balance additions or total supply calculations without adequate safeguards against integer overflow conditions. This allows an attacker with ownership privileges to input malicious values that cause the arithmetic operations to wrap around, resulting in unexpected balance manipulations. The vulnerability directly maps to CWE-190, which describes integer overflow and underflow conditions, and specifically aligns with CWE-682, representing incorrect arithmetic operations within software systems.
The operational impact of this vulnerability extends beyond simple balance manipulation to potentially compromise the entire token economy and user trust within the contract ecosystem. An attacker with owner privileges can artificially inflate or deflate user balances, effectively creating unlimited tokens or zeroing out balances, which directly impacts the token's utility and value. This flaw undermines the fundamental principles of blockchain tokenomics and can lead to significant financial losses for users who hold the affected tokens. The vulnerability also creates potential for coordinated attacks where malicious actors might manipulate token distributions to gain unfair advantages in token-based systems or prediction markets.
Mitigation strategies for this vulnerability require immediate implementation of proper input validation and overflow protection mechanisms within the smart contract code. The mintToken function must incorporate comprehensive checks to prevent arithmetic overflow conditions, including the use of SafeMath libraries or similar protection mechanisms that are standard in modern Ethereum smart contract development. Additionally, contract owners should implement proper access controls and audit procedures to prevent unauthorized modifications to critical functions. The vulnerability also highlights the importance of thorough smart contract auditing processes and adherence to established security standards such as those recommended by the OpenZeppelin security guidelines. Organizations should consider implementing multi-signature wallets for contract ownership and establishing regular security review processes to prevent similar vulnerabilities from being introduced in future contract implementations. This vulnerability demonstrates the critical importance of robust security practices in blockchain development environments where financial assets are at risk due to the immutable nature of smart contracts.