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C#

C# static code analysis

Unique rules to find Bugs, Vulnerabilities, Security Hotspots, and Code Smells in your C# code

  • All rules 493
  • Vulnerability46
  • Bug88
  • Security Hotspot24
  • Code Smell335

  • Quick Fix 61
Filtered: 14 rules found
bad-practice
    Impact
      Clean code attribute
        1. "ExcludeFromCodeCoverage" attributes should include a justification

           Code Smell
        2. Client instances should not be recreated on each Azure Function invocation

           Code Smell
        3. Azure Functions should be stateless

           Code Smell
        4. "is" should not be used with "this"

           Code Smell
        5. "Thread.Sleep" should not be used in tests

           Code Smell
        6. "nameof" should be used

           Code Smell
        7. Formatting SQL queries is security-sensitive

           Security Hotspot
        8. Loops with at most one iteration should be refactored

           Bug
        9. Tests should not be ignored

           Code Smell
        10. "switch" statements should have at least 3 "case" clauses

           Code Smell
        11. "GC.Collect" should not be called

           Code Smell
        12. Nested code blocks should not be used

           Code Smell
        13. "Obsolete" attributes should include explanations

           Code Smell
        14. Standard outputs should not be used directly to log anything

           Code Smell

        Formatting SQL queries is security-sensitive

        intentionality - complete
        maintainability
        security
        Security Hotspot
        • cwe
        • bad-practice
        • sql

        Formatted SQL queries can be difficult to maintain, debug and can increase the risk of SQL injection when concatenating untrusted values into the query. However, this rule doesn’t detect SQL injections (unlike rule S3649), the goal is only to highlight complex/formatted queries.

        Ask Yourself Whether

        • Some parts of the query come from untrusted values (like user inputs).
        • The query is repeated/duplicated in other parts of the code.
        • The application must support different types of relational databases.

        There is a risk if you answered yes to any of those questions.

        Recommended Secure Coding Practices

        • Use parameterized queries, prepared statements, or stored procedures and bind variables to SQL query parameters.
        • Consider using ORM frameworks if there is a need to have an abstract layer to access data.

        Sensitive Code Example

        public void Foo(DbContext context, string query, string param)
        {
            string sensitiveQuery = string.Concat(query, param);
            context.Database.ExecuteSqlCommand(sensitiveQuery); // Sensitive
            context.Query<User>().FromSql(sensitiveQuery); // Sensitive
        
            context.Database.ExecuteSqlCommand($"SELECT * FROM mytable WHERE mycol={value}", param); // Sensitive, the FormattableString is evaluated and converted to RawSqlString
            string query = $"SELECT * FROM mytable WHERE mycol={param}";
            context.Database.ExecuteSqlCommand(query); // Sensitive, the FormattableString has already been evaluated, it won't be converted to a parametrized query.
        }
        
        public void Bar(SqlConnection connection, string param)
        {
            SqlCommand command;
            string sensitiveQuery = string.Format("INSERT INTO Users (name) VALUES (\"{0}\")", param);
            command = new SqlCommand(sensitiveQuery); // Sensitive
        
            command.CommandText = sensitiveQuery; // Sensitive
        
            SqlDataAdapter adapter;
            adapter = new SqlDataAdapter(sensitiveQuery, connection); // Sensitive
        }
        

        Compliant Solution

        public void Foo(DbContext context, string query, string param)
        {
            context.Database.ExecuteSqlCommand("SELECT * FROM mytable WHERE mycol=@p0", param); // Compliant, it's a parametrized safe query
        }
        

        See

        • OWASP - Top 10 2021 Category A3 - Injection
        • OWASP - Top 10 2017 Category A1 - Injection
        • CWE - CWE-20 - Improper Input Validation
        • CWE - CWE-89 - Improper Neutralization of Special Elements used in an SQL Command
        • Derived from FindSecBugs rules Potential SQL/JPQL Injection (JPA), Potential SQL/JDOQL Injection (JDO), Potential SQL/HQL Injection (Hibernate)
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