C#


CSHARP.IO.TAINT.PATH : Tainted Path (C#)

要旨

Tainted data flows into a field annotated as [PathTrusted], or into a file path creation method.

See the OWASP page on Path Traversal for more information.

Checks for this class use the CodeSonar C# taint analysis. See Taint Tracking for CodeSonar C# Warning Classes for more information on this analysis, including lists of the methods that CodeSonar automatically recognizes as relevant and information about specifying additional methods that CodeSonar should recognize as taint sources, sinks, or sanitizers.

Use configuration parameter CSHARP_ANALYSIS_ADVANCED_INJECTION to specify the level of checking to perform for this and other taint-related warning classes:

プロパティ

クラス名 Tainted Path (C#)
日本語クラス名 Tainted Path (C#)
クラス分類 セキュリティ (security)
ニーモニック CSHARP.IO.TAINT.PATH
カテゴリー
CWE CWE:22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
OWASP-2017 OWASP-2017:A1 Injection
OWASP-2021 OWASP-2021:A3 Injection
対応言語 C# で利用可能です。
有効/無効設定 このワーニングクラスのチェックはデフォルトで有効になっています。チェックを無効にするにはプロジェクト設定ファイル (configuration file)に以下の WARNING_FILTER ルールを追加してください。
WARNING_FILTER += discard class="Tainted Path (C#)"

using System;
using System.IO;
using System.Net;

namespace DocumentationExample
{
    class OtherInjectionExamples
    {

        static void Main(string[] args)
        {
            string input = GetUserInput();

            CommandInjectionExample(input);
            PathInjectionExample(input);
            UrlInjectionExample(input);
        }

        private static String GetUserInput()
        {

            return Console.ReadLine();

        }

        private static void CommandInjectionExample(String input)
        {
            try
            {
                System.Diagnostics.Process.Start("CMD.exe", input); // Command Injection (C#) warning issued here 
            } catch (Exception e)
            {
                Console.WriteLine("invalid command: " + e.Message);
            }


        }

        private static void PathInjectionExample(string input)
        {
            try
            {
                File.Delete(input);                                 // Tainted Path (C#) warning issued here 
            } catch (Exception e)
            {
                Console.WriteLine("unable to delete file: " + e.Message);
            }
        }

        private static void UrlInjectionExample(String input)
        {

            try
            {
                WebRequest request = WebRequest.Create(input);      // Tainted URL (C#) warning issued here 
                // ...
 
                WebResponse response = request.GetResponse();

                using (Stream dataStream = response.GetResponseStream())
                {
                    StreamReader reader = new StreamReader(dataStream);
                    string responseFromServer = reader.ReadToEnd();
                    Console.WriteLine(responseFromServer);
                }

                response.Close();
            }
            catch (Exception e)
            {
                Console.WriteLine("request error: " + e.Message);
            }
        }
    }

}

解決法

Verify that a security error actually corresponds to unconstrained information flow from source locations into sink locations. If this is the case, add a sanitizing algorithm to clean data before it flows into sinks, or use prepared statements for SQL queries rather than free queries built from string concatenation.

関連のある設定ファイルパラメータ

設定ファイルの以下のパラメータがこのワーニングクラスのチェックに影響します。