Prevent shell injection

Docs > Code Analysis > Static Analysis Rules > Prevent shell injection

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Metadata

ID: csharp-security/shell-injection

Language: C#

Severity: Warning

Category: Security

CWE: 78

Description

Never build a command to execute manually by concatenating strings. Instead, validate each component of the command to ensure there is no user-input.

Learn More

CWE-78: Improper Neutralization of Special Elements used in an OS Command (‘OS Command Injection’)

Non-Compliant Code Examples

public class Sample
{
    public void myMethod(string myProgram)
    {
        Process p = new Process();
        p.StartInfo.FileName = "path/to/" + myProgram;
        p.Start();
    }
}

public class Runner {
    public static int Run(string cmd, string args, string input) {
        ProcessStartInfo startInfo = new ProcessStartInfo
        {
            WorkingDirectory = Settings.RootDir,
            FileName = cmd,
            Arguments = args,
            UseShellExecute = false,
            RedirectStandardInput = true,
            RedirectStandardError = true,
            RedirectStandardOutput = true,
        };
        using (Process process = new Process())
        {
            process.EnableRaisingEvents = true;
            process.StartInfo = startInfo;
            process.Start();
        }
    }
}