CVE-2018-13524 in PornCoin
Summary
by MITRE
The mintToken function of a smart contract implementation for PornCoin (PRNC), 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.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 02/27/2020
The vulnerability identified as CVE-2018-13524 resides within the mintToken function of the PornCoin (PRNC) smart contract implementation deployed on the Ethereum blockchain. This flaw represents a critical integer overflow vulnerability that fundamentally compromises the contract's ability to maintain accurate token balances and control access to the system. The vulnerability stems from improper input validation and arithmetic operations within the smart contract code, creating a scenario where the contract owner can manipulate user balances without legitimate authorization. Such a flaw directly violates the core principles of blockchain security and asset integrity that underpin decentralized applications.
The technical implementation of this vulnerability manifests through the mintToken function's handling of integer arithmetic operations that exceed the maximum value representable by the data types used in the contract. When the mintToken function processes token minting operations, it fails to properly validate input parameters, particularly the amount parameter that determines how many tokens to mint for a specific user. This oversight allows an attacker with owner privileges to craft malicious inputs that cause integer overflow conditions, enabling them to set arbitrary user balances to predetermined values. The vulnerability is classified as CWE-190, which specifically addresses integer overflow conditions, and aligns with the broader category of CWE-191, integer underflow. The underlying issue occurs because the contract does not implement proper bounds checking or overflow detection mechanisms that are essential for secure smart contract development.
The operational impact of this vulnerability extends beyond simple financial manipulation to encompass potential systemic risks within the token ecosystem. The ability to set arbitrary user balances enables the contract owner to create unlimited tokens for specific addresses, potentially leading to massive dilution of the token supply and complete loss of value for legitimate token holders. This vulnerability also creates opportunities for gaming the token economy by allowing the owner to artificially inflate balances of preferred accounts or create artificial demand for the token. The implications are particularly severe given that this vulnerability affects a publicly accessible Ethereum token, meaning that any individual with owner privileges can exploit this flaw without requiring additional network access or complex attack vectors. The vulnerability directly impacts the principle of immutability that smart contracts are designed to uphold, as it allows for unauthorized modifications to the contract's state.
Mitigation strategies for this vulnerability must address both immediate remediation and long-term architectural improvements to prevent similar issues in future smart contract implementations. The most effective immediate solution involves implementing comprehensive input validation and integer overflow protection mechanisms within the mintToken function, including explicit bounds checking and the use of safe arithmetic libraries such as OpenZeppelin's SafeMath. The contract owner should also implement proper access controls and audit trails to monitor any minting operations that occur within the system. Additionally, the vulnerability highlights the importance of thorough smart contract auditing and adherence to established security frameworks such as the Secure Development Lifecycle for blockchain applications. Organizations should implement regular security assessments and consider using formal verification methods to detect potential overflow conditions before deployment. The remediation process should also include a complete audit of all arithmetic operations within the smart contract to ensure that similar vulnerabilities do not exist in other functions. This vulnerability serves as a critical reminder of the importance of following established security standards and best practices in smart contract development, particularly in the context of financial applications where such flaws can have catastrophic consequences for token holders and the broader ecosystem.