Smart Contract / Outdated Compiler Version

Description

Outdated Compiler Version is a type of vulnerability classified under the Smart Contract category (CWE-827) of the Common Weakness Enumeration (CWE). It is a vulnerability that occurs when the source code of a smart contract is compiled with an out-of-date compiler version. This can result in the code not being securely compiled and therefore potentially vulnerable to malicious attacks. As per the OWASP Testing Guide, it is important to ensure that the compiler version used for compiling the code is up-to-date and supports all security features.

Risk

Outdated Compiler Version can lead to a variety of security risks. If the code is not securely compiled, it could allow attackers to bypass security features such as authentication and authorization, tamper with data, or even steal funds. In addition, the outdated compiler version might not be able to detect and protect against vulnerable code patterns, making the code more susceptible to attacks.

Solution

The solution to this vulnerability is to ensure that the compiler version used to compile the source code is up-to-date and supports all security features. This can be done by regularly checking for updates, as well as ensuring that the compiler is kept up-to-date with the latest security patches. Additionally, the code should be tested for any potential vulnerabilities prior to deployment, and any identified vulnerabilities should be addressed immediately.

Example

The following code is an example from the Common Vulnerabilities and Exposures (CVE) directory that shows an example of an outdated compiler version vulnerability.

contract MyContract {
  //...
  function foo() public {
    //...
    uint256 x = 42; // vulnerable line
    //...
  }
  //...
}

In this example, the code is compiled with an outdated compiler version which does not support the “uint256” type. As a result, the value of “x” is not correctly validated, making the code vulnerable to malicious attacks.