CVE-2018-13711 in Databits
Summary
by MITRE
The mintToken function of a smart contract implementation for Databits, 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 • 02/28/2020
The vulnerability identified in CVE-2018-13711 represents a critical integer overflow flaw within the mintToken function of the Databits Ethereum token smart contract implementation. This vulnerability stems from inadequate input validation and overflow protection mechanisms that are fundamental requirements for secure smart contract development. The flaw allows the contract owner to manipulate user balances arbitrarily, effectively compromising the integrity of the token economy and potentially enabling unauthorized fund transfers or account manipulation. The vulnerability manifests when the mintToken function processes token minting operations without proper bounds checking, creating conditions where arithmetic operations can exceed maximum integer limits and wrap around to unexpected values.
The technical nature of this vulnerability aligns with CWE-190, which specifically addresses integer overflow and underflow conditions in software implementations. In the context of Ethereum smart contracts, this represents a severe design flaw that violates core security principles of decentralized applications. The integer overflow occurs during the balance calculation process within the mintToken function, where the contract fails to validate that the resulting balance value remains within acceptable numerical bounds. This allows an attacker with owner privileges to craft malicious inputs that cause the balance arithmetic to overflow, resulting in arbitrary balance manipulation. The vulnerability is particularly dangerous because it operates at the contract level, meaning the owner can manipulate any user's balance to any desired value, including potentially setting balances to zero or extremely high values.
The operational impact of this vulnerability extends far beyond simple balance manipulation, as it fundamentally undermines the trust model that underpins cryptocurrency systems. When a contract owner can arbitrarily set user balances, it creates potential for financial loss, market manipulation, and systematic disruption of the token's economic model. The vulnerability enables scenarios where malicious actors could drain user accounts, create artificial scarcity, or manipulate token distribution to their advantage. From an attacker's perspective, this represents a critical privilege escalation vector that allows for unauthorized control over user assets. The implications are severe for token holders who rely on the contract's integrity and for the broader ecosystem that depends on predictable and secure token operations.
Mitigation strategies for this vulnerability must address both immediate remediation and long-term architectural improvements to prevent similar issues in future smart contract deployments. The primary fix involves implementing comprehensive input validation and overflow protection mechanisms within the mintToken function, including explicit bounds checking and use of safe arithmetic libraries such as OpenZeppelin's SafeMath. Additionally, contract owners should implement proper access control measures and consider adopting more robust contract design patterns that minimize privileged account usage. The vulnerability also highlights the importance of thorough security auditing and formal verification processes for smart contracts, as recommended by industry standards and best practices. Organizations should implement comprehensive testing procedures including fuzz testing and symbolic execution to identify potential integer overflow conditions before deployment. The remediation process should also include regular security assessments and code reviews to ensure that similar vulnerabilities do not persist in other contract functions or future iterations of the codebase, as demonstrated by the ATT&CK framework's emphasis on persistent threats and privilege escalation techniques that exploit such fundamental implementation flaws.