CVE-2018-13479 in SlidebitsToken
Summary
by MITRE
The mintToken function of a smart contract implementation for SlidebitsToken, 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 as CVE-2018-13479 represents a critical integer overflow flaw within the mintToken function of the SlidebitsToken smart contract deployed on the Ethereum blockchain. This vulnerability stems from improper input validation and arithmetic operations that fail to account for the maximum limits of integer data types. The flaw allows the contract owner to manipulate token balances by creating an overflow condition that can result in arbitrary balance modifications for any user within the system. The vulnerability directly maps to CWE-191, which specifically addresses integer underflow and overflow conditions, and demonstrates a fundamental lack of proper boundary checking in smart contract arithmetic operations. The implications extend beyond simple balance manipulation as this flaw can potentially enable unauthorized wealth creation or destruction within the token economy.
The technical execution of this vulnerability occurs through the mintToken function where the contract owner can manipulate the token supply by exploiting an unchecked integer overflow condition. When the mintToken function processes token creation requests, it fails to validate whether the resulting token balance would exceed the maximum value that can be represented by the underlying integer data type. This oversight allows the owner to perform mathematical operations that wrap around the integer limits, effectively allowing them to set any user's balance to an arbitrary value including zero, maximum values, or negative representations. The vulnerability is particularly dangerous because it operates within the contract's privileged owner account, providing direct control over the token distribution mechanism without requiring external attack vectors. The flaw can be exploited through simple transaction manipulation where the owner submits carefully crafted parameters to trigger the overflow condition.
The operational impact of CVE-2018-13479 extends far beyond the immediate financial implications, potentially destabilizing the entire token economy and eroding user trust in the platform. An attacker with owner privileges can manipulate token distributions to create artificial scarcity or abundance, potentially leading to market manipulation and financial losses for other token holders. The vulnerability creates an attack surface that allows for unauthorized balance modifications, which can be used to drain funds from other users or artificially inflate the balances of specific accounts. This type of flaw represents a significant risk to blockchain-based financial systems as it undermines the fundamental principle of secure and predictable token accounting. The vulnerability also creates potential for exploitation through social engineering or compromised owner accounts, where an attacker could gain control and manipulate token balances for personal gain. The impact is particularly severe in decentralized finance applications where token balances directly correlate to financial value and access rights.
Mitigation strategies for CVE-2018-13479 must focus on implementing robust input validation and proper integer overflow protection within smart contract code. The most effective approach involves using safe arithmetic libraries or implementing explicit bounds checking before any arithmetic operations that could potentially overflow. Contracts should utilize require statements to validate input parameters and ensure that operations remain within acceptable ranges before execution. The implementation of overflow protection mechanisms such as OpenZeppelin's SafeMath library provides a standardized approach to preventing these types of vulnerabilities. Additionally, regular security auditing and formal verification of smart contracts should be implemented to identify potential integer overflow conditions before deployment. The vulnerability highlights the importance of adhering to security best practices outlined in the CWE guidelines and implementing defensive programming techniques that prevent arithmetic overflows. Organizations should also consider implementing multi-signature ownership models and regular access control reviews to minimize the risk of unauthorized exploitation, aligning with attack techniques documented in the MITRE ATT&CK framework for smart contract security.