Detecting Code Smells with Static Analysis in Security Testing Quiz

Explore key concepts of identifying code smells using static analysis within security testing. This quiz covers practical scenarios, detection techniques, and the impact of code smells on software security and maintainability.

1. Identifying a Common Code Smell

   During static analysis, a function consistently exceeds 200 lines and handles multiple responsibilities, such as data input, processing, and output. What type of code smell does this scenario most likely represent?

   1. God Function
   2. Dead Store
   3. Unreachable Code
   4. Shadowing Variable

   Explanation: A 'God Function' describes a function that does too much by handling several unrelated responsibilities or growing excessively large, making it difficult to maintain or test. 'Dead Store' refers to variables assigned values that are never used. 'Unreachable Code' is code that cannot be executed under any scenario, and 'Shadowing Variable' occurs when a variable declaration hides another variable. In this case, the primary problem is the oversized, multi-responsibility function, fitting the 'God Function' code smell.

2. Static vs. Dynamic Analysis

   Which of the following best explains how static analysis can reveal security code smells as compared to dynamic analysis?

   1. Static analysis inspects code without execution and can flag insecure patterns such as hardcoded credentials.
   2. Static analysis requires program execution to trace attacks at runtime.
   3. Static analysis automatically prevents code smells from being introduced.
   4. Static analysis only checks syntax errors that do not relate to security.

   Explanation: Static analysis examines code structure and patterns without running the program and can identify potential security code smells like hardcoded credentials. Dynamic analysis, in contrast, inspects code during execution but may not catch static patterns. Static analysis does not automatically prevent code smells nor is it limited to syntax errors; it looks deeper into code semantics. Thus, identifying code issues without execution is a key feature of static analysis.

3. Recognizing 'Duplicate Code' Smell

   If a static analysis tool flags several identical blocks of code in separate functions, which code smell is being detected, and what is a likely reason this impacts security?

   1. Duplicate Code; increases risk of inconsistent security fixes
   2. Cyclomatic Complexity; causes code to crash more easily
   3. Code Injection; always results in buffer overruns
   4. Singleton Pattern; reduces code readability

   Explanation: Duplicate code means similar or identical code appears in multiple locations, which makes it easy to miss essential updates or fixes, especially for security issues. Cyclomatic complexity refers to the number of possible code paths, not duplication. Code injection is a type of vulnerability, not a code smell, and singleton pattern is a design choice rather than a code smell impacting duplication. Keeping code DRY (Don't Repeat Yourself) ensures more consistent security updates.

4. Detecting 'Dead Code' and Its Risks

   A static analysis tool reports several functions and variables that are never used or referenced anywhere in the codebase. What is the term for this code smell, and why could it be a security concern?

   1. Dead Code; it may hide vulnerabilities overlooked during review
   2. Memory Leak; rapidly consumes more system RAM
   3. Type Inference; creates ambiguity in data types
   4. Tight Coupling; makes the code more modular

   Explanation: Dead code refers to code that is present but never used or called, and it can hide vulnerabilities or outdated logic that does not receive sufficient security review. Memory leaks are runtime issues, not static code smells. Type inference and tight coupling are unrelated to unused code and do not directly relate to hidden vulnerabilities stemming from dead code. Removing dead code helps make security reviews more effective.

5. Code Smells Preceding Insecure Coding Patterns

   Which situation most clearly indicates a code smell that could precede a security risk, as detected by static code analysis?

   1. A function executes SQL queries with direct user input concatenation
   2. A function name is misspelled but matches its references
   3. A variable is declared as 'global' but never used in the code
   4. All comments in the program are written in uppercase letters

   Explanation: Directly inserting user input into SQL queries without validation or parameterization is a code smell that often leads to SQL injection vulnerabilities. A misspelled but referenced function name presents a naming issue, not a primary security risk. An unused global variable may be dead code, but it does not immediately signal a security problem. The casing in comments is irrelevant to security. Thus, unsafe string concatenation for SQL queries is the most direct security-relevant code smell in this list.