CVE-2018-13497 in COBToken
Summary
by MITRE
The mintToken function of a smart contract implementation for COBToken, 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 in CVE-2018-13497 represents a critical integer overflow flaw within the mintToken function of the COBToken smart contract implementation 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 setting them to arbitrary values, fundamentally compromising the integrity of the token distribution mechanism and potentially enabling unauthorized wealth transfer between accounts.
The technical execution of this vulnerability occurs through the mintToken function which likely performs arithmetic operations without proper overflow checks or boundary validations. When the contract owner invokes this function with specific parameters, the integer overflow condition is triggered, allowing manipulation of the target user's balance to any desired value. This type of vulnerability maps directly to CWE-190, which specifically addresses integer overflow and underflow conditions in software implementations. The flaw exists at the core level of the token contract logic where the mint function should only increment balances but instead enables arbitrary value assignment through mathematical overflow exploitation.
The operational impact of this vulnerability extends far beyond simple balance manipulation, creating significant risks for token holders, investors, and the broader Ethereum ecosystem. An attacker with owner privileges can effectively drain funds from other users or inflate their own holdings, potentially leading to total loss of value for the token. This vulnerability undermines the fundamental trust in the smart contract system and can result in complete financial loss for token holders. The attack vector is particularly dangerous because it requires only owner privileges, which are typically limited to a small number of trusted parties, making the impact more severe when compromised.
Mitigation strategies for CVE-2018-13497 must address both immediate remediation and long-term security hardening of smart contracts. The primary fix involves implementing proper integer overflow protection mechanisms such as using safe math libraries, adding explicit boundary checks before arithmetic operations, and ensuring all integer calculations respect data type limits. Organizations should adopt security frameworks like the OpenZeppelin SafeMath library or similar implementations that provide overflow-checked arithmetic operations. Additionally, comprehensive code auditing and formal verification processes should be implemented to identify similar vulnerabilities across the entire smart contract ecosystem, following ATT&CK framework principles for smart contract security assessments. Regular security updates and multi-signature ownership structures can also reduce the risk of exploitation by limiting single points of failure in contract administration.