CVE-2018-13480 in QRG
Summary
by MITRE
The mintToken function of a smart contract implementation for QRG, 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 described in CVE-2018-13480 represents a critical integer overflow flaw within the mintToken function of the QRG Ethereum token smart contract implementation. This vulnerability falls under the CWE-190 category of Integer Overflow or Wraparound, which occurs when a program performs arithmetic operations on integer values that exceed the maximum representable value for the data type. The specific implementation flaw allows the contract owner to manipulate token balances through improper handling of integer arithmetic during token minting operations.
The technical execution of this vulnerability stems from inadequate input validation and overflow checking within the mintToken function. When the owner attempts to mint tokens for a user, the smart contract fails to properly validate the input parameters, particularly the amount parameter that determines how many tokens to mint. This oversight creates an opportunity for an attacker with owner privileges to craft malicious inputs that cause integer overflow conditions, enabling them to manipulate user balances to arbitrary values. The vulnerability specifically affects the balance tracking mechanism within the token contract, allowing for unauthorized manipulation of token distributions.
The operational impact of this vulnerability is severe and multifaceted, as it fundamentally compromises the integrity of the token economy. An attacker with owner access can increase any user's balance to extremely high values, potentially leading to massive inflation of the token supply or manipulation of token distributions. This could result in significant financial losses for legitimate token holders, as the attacker could artificially inflate their own holdings or manipulate market dynamics. The vulnerability also undermines trust in the smart contract system and the underlying token, as it demonstrates a fundamental flaw in the contract's security design that could be exploited for financial gain.
From a security perspective, this vulnerability aligns with ATT&CK technique T1548.001 for privilege escalation and T1499.004 for data manipulation. The attack vector leverages the owner account's elevated privileges to manipulate contract state through integer overflow exploitation, bypassing normal access controls and validation mechanisms. Organizations and developers should implement comprehensive input validation, utilize safe arithmetic libraries, and conduct thorough security audits of smart contracts before deployment. The vulnerability highlights the critical importance of proper integer handling in blockchain smart contracts, as these environments execute code with direct financial consequences. Mitigation strategies include implementing overflow checks, using established secure coding practices, and conducting regular security assessments to identify similar vulnerabilities in token implementations and other blockchain applications.
The broader implications extend beyond this specific vulnerability to highlight systemic security issues in smart contract development. This flaw demonstrates how seemingly minor implementation oversights can create significant financial risks in decentralized applications, emphasizing the need for robust security frameworks and comprehensive testing procedures. The vulnerability also underscores the importance of using formal verification techniques and security-focused development practices in blockchain environments where code execution cannot be easily modified after deployment.