CVE-2018-13537 in EthereumLegit
Summary
by MITRE
The mintToken function of a smart contract implementation for EthereumLegit, 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.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 02/27/2020
The vulnerability identified as CVE-2018-13537 represents a critical integer overflow flaw within the mintToken function of the EthereumLegit token smart contract implementation. This vulnerability resides in the core token functionality that governs the creation and distribution of new tokens within the Ethereum blockchain ecosystem. The integer overflow occurs when the smart contract fails to properly validate or constrain numeric inputs during token minting operations, creating a condition where arithmetic operations can exceed the maximum representable value for the data type being used. Such overflow conditions typically arise when developers fail to implement proper bounds checking or use of safe arithmetic libraries in their smart contract code, leaving the system susceptible to malicious manipulation through carefully crafted input values that trigger the overflow behavior.
The operational impact of this vulnerability is severe and directly enables the contract owner to manipulate user balances arbitrarily within the token system. When an integer overflow occurs in the mintToken function, it creates a scenario where the owner can effectively bypass normal token distribution mechanisms and directly control account balances. This represents a fundamental breach of trust in the token system, as the owner gains the ability to inflate or deflate any user's token balance without legitimate justification. The vulnerability allows for potentially unlimited token creation or manipulation of existing balances, which could result in significant financial losses for token holders and undermine the entire economic model of the token system. The flaw essentially provides the contract owner with a backdoor mechanism to manipulate the token supply and user holdings, making the system vulnerable to both accidental and intentional abuse.
From a cybersecurity perspective, this vulnerability aligns with CWE-190, which specifically addresses integer overflow and underflow conditions in software implementations. The flaw demonstrates poor secure coding practices in smart contract development, where developers fail to implement proper input validation and arithmetic safety measures. The ATT&CK framework categorizes this as a privilege escalation technique, as the vulnerability allows an attacker with owner privileges to gain expanded control over the token distribution mechanism. The vulnerability also relates to CWE-699, which covers the broader category of software vulnerabilities that can lead to unauthorized access or manipulation of system resources. Additionally, this type of vulnerability falls under the broader category of smart contract security flaws that have become increasingly prevalent as blockchain-based applications have grown in complexity and adoption.
Mitigation strategies for this vulnerability require immediate implementation of proper input validation and arithmetic safety measures within the smart contract code. Developers must ensure that all numeric operations include proper bounds checking and utilize safe arithmetic libraries or overflow protection mechanisms. The recommended approach involves implementing explicit checks to prevent overflow conditions before performing arithmetic operations, particularly in functions that manipulate token balances or supply. Contract owners should also consider implementing multi-signature controls or time locks on critical functions to prevent unauthorized execution of vulnerable operations. Additionally, comprehensive code auditing and formal verification techniques should be employed to identify and remediate similar vulnerabilities across the entire smart contract system. The vulnerability underscores the critical importance of adhering to established secure coding practices in blockchain development and highlights the need for robust testing methodologies including fuzz testing and symbolic execution to identify potential arithmetic overflow conditions before deployment.