CVE-2018-10973 in KoreaShow
Summary
by MITRE
An integer overflow in the transferMulti function of a smart contract implementation for KoreaShow, an Ethereum ERC20 token, allows attackers to accomplish an unauthorized increase of digital assets via crafted _value parameters.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 02/04/2020
The vulnerability identified as CVE-2018-10973 represents a critical integer overflow flaw within the transferMulti function of the KoreaShow ERC20 token smart contract deployed on the Ethereum blockchain. This issue stems from inadequate input validation and arithmetic overflow handling within the contract's implementation, creating a pathway for malicious actors to manipulate token balances through carefully crafted parameters. The vulnerability specifically affects the transferMulti function which is designed to facilitate batch transfers of tokens to multiple recipients simultaneously, making it a particularly dangerous flaw given its potential for widespread impact across multiple transactions.
The technical exploitation of this vulnerability occurs through integer overflow conditions in the underlying arithmetic operations that handle token value calculations. When attackers provide maliciously constructed _value parameters to the transferMulti function, the contract fails to properly validate the input values against the maximum limits of the integer data types being used. This allows the overflow to occur during calculations, resulting in unexpected behavior where the token amounts are manipulated in ways that bypass normal transfer restrictions and authorization mechanisms. The flaw is categorized under CWE-190 as an integer overflow condition, specifically manifesting as an unsigned integer overflow in the context of smart contract token management operations. This vulnerability directly enables unauthorized asset manipulation by allowing attackers to create token balances that exceed normal operational limits.
The operational impact of CVE-2018-10973 extends beyond simple unauthorized token transfers, potentially enabling attackers to create unlimited token supply or manipulate account balances in ways that could destabilize the entire token economy. The vulnerability affects the integrity and availability of the token system by allowing unauthorized increases in digital assets, which undermines the fundamental trust model that ERC20 tokens rely upon for their value and security. This flaw particularly impacts the token's transfer mechanism and could enable attackers to drain funds from other users' accounts or create artificial inflation of token supply. The vulnerability also has implications for the contract's overall security posture, as it demonstrates poor defensive programming practices that could expose other functions within the same smart contract to similar attacks. According to ATT&CK framework category T1548.003, this vulnerability enables privilege escalation through code injection and manipulation of contract state, effectively allowing attackers to gain unauthorized control over token balances.
Mitigation strategies for CVE-2018-10973 require immediate implementation of comprehensive input validation and integer overflow protection mechanisms within the smart contract code. Developers should implement explicit bounds checking for all arithmetic operations, particularly when handling token values that could potentially overflow standard integer data types. The recommended approach involves using overflow-safe arithmetic libraries or implementing explicit overflow detection before performing calculations, ensuring that all mathematical operations respect the maximum limits of the underlying data types. Additionally, smart contract audits should be conducted to identify similar patterns across other functions within the same contract, as integer overflow vulnerabilities often appear in multiple locations within complex smart contract implementations. The vulnerability also necessitates the implementation of proper access controls and transaction validation mechanisms to prevent unauthorized modifications to token balances, aligning with security best practices outlined in the Ethereum Smart Contract Security Best Practices document. Regular security testing and continuous monitoring of smart contract behavior should be implemented to detect potential exploitation attempts and ensure the ongoing integrity of token systems.