[Day 1] 3. Software Vulnerabilities

What is a Software Bug?

• A software bug is a flaw in a program that causes it to behave unexpectedly.

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What is VAPT (Vulnerability Assessment and Penetration Testing)?

• Purpose: Identifies vulnerabilities (weaknesses) in a system.
• Example: Testing for flaws that could compromise system security.

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World's Costliest Vulnerability: ARIANE 5 Case Study

• Event: European Space Agency's ARIANE 5 rocket failure.
• Cause: A program tried to fit a 64-bit number into a 16-bit space, leading to catastrophic failure.

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What is a Vulnerability?

• A weakness that threatens the confidentiality, integrity, or availability of an asset.

• It exists due to a lack of countermeasures. Types of Vulnerabilities:

  1. Design Vulnerability: Fault in the system's design.
     • Example: Flaws in the TCP/IP stack.
  2. Implementation Vulnerability: Correct design but faulty implementation.
     • Example: Buffer overflows.
  3. Operational/Configurational Vulnerability: Correct design and implementation but poor configuration or operation.
     • Example: Using default usernames/passwords on critical devices.

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Threats, Risks, and Countermeasures

• Threat: Potential danger to systems or information.
  • Example: An attacker exploiting a vulnerability.
• Risk: The probability of a threat occurring.

Risk Management Process:

1. Identify Risk
2. Assess Risk
3. Control Risk
4. Review Risk

Exposure:

• Sharing information unnecessarily, which can lead to vulnerabilities.

Countermeasure:

• Security measures to reduce risk, such as firewalls or antivirus software.

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Quality of Service (QoS)

• Purpose: Prioritizes certain types of packets for better performance.
• Example:
  • During a live match, radio audio is delivered faster than live-stream video due to prioritization of audio packets over video packets.
• QoS Field: A field in packets (that carry the data) that determines priority levels.

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FUS Triangle

• Functionality, Usability, and Security
  • Balancing these three aspects is crucial for robust systems.

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Defense in Depth

• Also known as Castle Approach or Elastic Defense.
• Protects assets using multiple layers of defense, which can be added or removed as required.

Defense Layers:

1. Data Defenses (e.g., encryption)
2. Application Defenses (e.g., secure coding practices)
3. Host Defenses (e.g., endpoint protection)
4. Network Defenses (e.g., firewalls)
5. Perimeter Defenses (e.g., intrusion detection systems)
6. Physical Security (e.g., locks and surveillance)
7. Policies, Procedures, and Awareness (e.g., employee training).

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