Common Solutions for Smart Contract Security Bugs

As more businesses navigate towards blockchain, crypto, and Ethereum technologies for generating more revenue or brand value for the company, it is highly recommended to use the appropriate systems for the development and maintenance of the smart contracts associated with these programs. Ideally, blockchain engineers will be able to diagnose smart contract errors due to the common occurrence of repeated bugs associated with these programs; however, for additional assistance, software developers may apply different applications to better prevent these potential errors or resolve issues as they appear. 

There are numerous different ways to securitize your smart contracts, stay up to date on the latest smart contract security practices, and prevent common issues and bugs associated with Smart Contracts by using third-party tools suited for your business needs. To learn more about blockchain development services and the crypto technologies best suited for your business, enterprises may reach out to a local Los Angeles blockchain development company, like Sunlight Media

Common Smart Contract Bugs

Spending time to understand how exactly smart contracts function and become inactive is vital for your business. It may significantly benefit your business to run routine audits on your blockchain and crypto technologies, to maintain productivity. Generally, smart contracts undergo different types of bugs, errors, and threats when active and on the network. For instance, there are reentrancy, unauthorized access, external calls, logic, integer underflow and overflow, data storage, and gas overflow integration bugs.  

What are Smart Contracts? 

In general, a smart contract runs on blockchain programs and automatically executes a function once specific criteria, conditions, scenarios, or agreements are met with single or multiple participants or machines. These smart contract audit practices and tools assist blockchain and crypto developers with better analyzing code structures, defining inheritance maps, testing scenarios of inputs and outputs, and running possible scenarios to ensure smart contract functionality and efficiency. 

Depending on the auditing system used, they may be downloaded onto local Linux, Windows, or Mac servers and vary in complexity, comprehensivity, and user-friendliness. Below is a list of common smart contract errors that may be prevented from running an audit. Along with the list of potential smart contract errors, the descriptions provided may also include the reason for occurrence and potential solutions for each described error. 

Common Solutions for Smart Contract Security Bugs


Bugs involving reentrancy may occur during moments when a smart contract is running processes on complex sequences involving multiple participants or servers. In other words, a user requesting a program to perform a function within a smart contract may perform that request numerous times in one sitting, which may result in users performing numerous requests before the first execution of the function may be successfully fulfilled. 

Due to the repeated calling function, users working with this particular faulty function may be able to withdraw funds or files multiple times without having permission to do so. The common solution for reentrancy bugs is through the use of a Mutex (execution limiter on the access of resources that overrides primary base functions) or by following a Checks-Effects-Interactions security audit to ensure that the system will lock upon the first called request. 

Unauthorized Access

In most cases, visitors to a website or a customer interacting with a brand’s products and services may be led through a conversion funnel to assist end-users with navigation or maximizing potential end-sale. In other words, end-users do not typically have access to back-end Admin dashboards or exclusive offers designated for premium members or other associated user accounts. 

The Unauthorized Access bug malfunctions when an important function does not recall any restrictions. This may lead to “leaked” private statements, recordings, or files that suddenly become available for the public, which may cause potential issues in the short or long run. In these instances, software developers may exercise a price update callback or reassign a value in a smart contract, such as price, which may be spruced from public forums or databases.  

External Calls 

Typically, associated with Ethereum blockchains, the term “gas” is interchangeably known as a cost for performing transactions within the network. During these transactions, the smart contract may have built-in programming with exceptions and fallback criteria for when funds do not meet minimum requirements. As a result, the price pre-determined by the “miner” may prevent users from completing a transaction since the exact price was met by the user, therefore indicating a default that not enough funds were delivered. 

Due to this error in the exception, an external call will signal for an “out-of-gas” function. Although this snippet within the smart contract is designed to prevent vulnerabilities in smart contracts, like reentrancy bugs, the function must be enabled as a constant for gas usage to accept nominal values from users involved with network transactions. As a recommendation, software and blockchain developers may check return values from smart contract call methods and follow Checks-Effects-Interactions. 

For more information about blockchain “gas” insights, businesses may review what is Ethereum gas

Code Logic Errors 

Both Ethereum and DApps feature smart contracts with different functional specifications following logical code configuration for performance. Due to the structural integrity required within these programs, developers may source a functional code, but may not have determined a secondary call-back in instances of system vulnerabilities or hacker and cyber attacks. 

For this reason, developers using smart contracts in conjunction with blockchain, crypto, and Ethereum platforms and systems may be required to provide data scripts that other developers may easily reference to ensure smart contract productivity and performance on the network.

Integer Overflow and Underflow

Depending on the system’s set preferences, an integer overflow or underflow bug may occur when certain numerical inputs are too small or too big for the computational ability to support. A simple example would be how an input for a numerical value does not validate when using integers too low or too big for the system to recognize. Software and Ethereum engineers may devise built-in validations to recognize different integers. 

Incorrect Storage of Private Data

A common error associated with smart contracts occurs when developers store sensitive information or data within the Ethereum contract or mistakenly assign different values for private, internal, or restricted permissions. For instance, a blockchain developer may use various keywords within their smart contract programming, which may unexpectedly call an unintended result. 

This may prove costly for end-users as they may input transaction data or store files within the system, which may be redirected to an internal system. These errors within the code may then corrupt private or stored data used when interacting with smart contracts.  

Gas Overflow

For clarification, blockchain stores different data onto different data blocks as a way to decentralize data processed and the security involved with transactions. In instances where “loops,” are part of the system’s normal functions, a potential bug may appear when the maximum “gas” limit exceeds the data accepted per each data block. This overflow may cause issues such as specific transactions failures and eventually permanent account blocks with increased frequency. 


In conclusion, smart contracts may be developed to carry out operations such as transactions, downloads, and storage of data in an effective, efficient, and secure manner if designed and tested properly. While qualified software and blockchain developers may configure blockchain technologies to utilize various smart contract functions, it is of the utmost importance to run different diagnostic and testing programs and applications to ensure smart contract maintenance and business productivity. 


Jhonathon Badalof works at Sunlight Media LLC in Downtown Los Angeles, California. As a Project Manager, Jhon collaborates with clients on website and app design and development, marketing, and creative solutions for campaigns. In addition to Project Management, Jhon is a content writer who writes articles that rank well on Google and other social media platforms. His skill sets include social media marketing, eCommerce, brand development, programming, web design, and graphic design.

Related Articles

Back to top button