Secure Programming - CSS-2751

Buffer Overflow: A failure of memory management when data input to a section of memory "overflows" that segment, overwriting data in other memory sections.
Code Injection: The process of inserting additional code into an application, often via unsanitized input to an interpreter.
Input Validation/Sanitization: Ensures user-provided input complies with expected data types and scrubs input before use.
Defense In Depth: A layered security policy that protects subjects even if one layer fails.
Principle of Least Privilege: Ensures users or programs have the minimum level of access necessary to perform their functions.
Default Deny/Whitelist: Security approach that denies all access unless explicitly allowed.
Static Analysis: Examination of source code or compiled code for errors without executing the program.
Dynamic Analysis: Tests run on an actively running program or device.
Fuzzing: An automated testing method feeding random or invalid input to a device to uncover crashes or exploits.
Black-Box Testing: Testing approach where the tester has no knowledge of the internal workings of the system.
White-Box Testing: Testing approach where the tester has full knowledge of the system, including source code and hardware.

Definition: A buffer overflow is a failure of memory management, where input data exceeds boundaries of a memory segment, potentially overwriting critical data in memory.
Impact: Attackers can exploit buffer overflows to overwrite data in executable areas and execute malicious code.
Protective Measures:
- Ensure all input data is within predefined memory bounds.
- Implement memory layout randomization to prevent predictable memory exploitation.

Definition: Code injection occurs when malicious code is inserted into an application through unsanitized user input to an interpreter.
Examples: This can range from a simple line of code to complex libraries like DLL files.
Consequences: The injected code can alter application behavior, access databases, install malware, or elevate user privileges.

Input Validation: The process of checking user input against expected formats and types (can be whitelist or blacklist based).
Input Sanitization: The scrubbing process that modifies user input to eliminate potentially harmful elements.
- Example: Ensuring user input to a SQL database is treated as data and not as SQL commands.
- Also involves removing special characters to prevent injection attacks.

Static Analysis: Involves reviewing source code or compiled binaries without executing them. It typically focuses on identifying common coding mistakes and adherence to coding standards.
Dynamic Analysis: Involves testing and analyzing the behavior of a running program or device. It evaluates the actual execution environment of code.

Definition: Fuzzing is an automated testing method that inputs random or invalid data to a program to find unintended behaviors or crashes.
Objective: To discover inputs close enough to valid that the system does not reject them, yet unexpected enough to cause failure.
Example Anecdote: "A Software QA Tester walks into a bar…" depicts absurd commands to illustrate unexpected program behavior resulting from chaotic inputs.

Black-Box Testing: The tester operates without knowledge of the internal workings of the target system, only understanding what the system is meant to do.
White-Box Testing: The tester has comprehensive knowledge of the system, including internal mechanisms and code structure, facilitating in-depth evaluation and testing.

Definition: A program initiated by companies to invite ethical hackers to discover and report potential exploits.
Reward System: Ethical hackers receive compensation or incentives for identifying vulnerabilities, fostering a collaborative effort to enhance security.

Concept: DiD refers to a layered approach to security where multiple defensive measures operate simultaneously to mitigate various risks.
- Recognizes that vulnerabilities may exist even within seemingly secure code, necessitating protective layers.
- Examples: Combining strong administrative access controls, firewalls, antivirus software, and sandboxing techniques to ensure broad protection.

Principles:
- Source code should be readable and understandable to facilitate audits and updates, moving away from security through obscurity.
- Ensure any reused code is secure; avoid using outdated or legacy code with known vulnerabilities.
- Employ strong encryption standards for data in transfer.
- Adopt a mindset of skepticism; always prioritize prevention and reporting of security breaches over merely recovering from attacks.