{"id":2791,"date":"2018-05-25T07:49:34","date_gmt":"2018-05-25T07:49:34","guid":{"rendered":"http:\/\/nethemba.com\/summary-of-the-common-smart-contracts-vulnerabilities\/"},"modified":"2018-05-28T05:58:57","modified_gmt":"2018-05-28T05:58:57","slug":"summary-of-the-common-smart-contracts-vulnerabilities","status":"publish","type":"post","link":"https:\/\/nethemba.com\/sk\/summary-of-the-common-smart-contracts-vulnerabilities\/","title":{"rendered":"Summary of the common smart contracts vulnerabilities"},"content":{"rendered":"

Introduction<\/span><\/h1>\n

Cryptocurrencies and blockchain technology gained a lot of attention in the last year due to increasing mainstream adoption and new use cases. Thanks to hundreds of completed ICOs launched on Ethereum platform, Solidity is one of the most popular languages for smart contracts development. With billions of dollars at play and relatively low-level of smart contract security enlightenment, smart contracts written in Solidity have been successfully exploited by a malicious user, and hundreds of millions worth of crypto funds have been stolen.<\/span><\/p>\n

The goal of this article is to highlight frequent security vulnerabilities of contracts written in Solidity language and explain ways how to identify and mitigate them.<\/span><\/p>\n

 <\/p>\n

Dangerous assumptions<\/span><\/h1>\n

Here is a list of assumptions one smart contract developer should <\/span>NOT <\/b>make to stay out of trouble.<\/span><\/p>\n

 <\/p>\n

\u201cNo one can send funds to my contract unless I allow them to\u201d<\/span><\/h2>\n

In Solidity, for a contract to be able to receive funds, at least one function has to be marked as \u2018payable\u2019. However, there are two special ways how someone can \u201cforce send\u201d funds to your contract even if none of the functions in your contract is marked as \u2018payable\u2019:<\/span><\/p>\n