CCNA Secure Software Concepts Questions

MCQhard

An application utilizes the Clark-Wilson integrity model. Which mechanism does it use to ensure that subjects only perform authorized operations on objects?

A.Role-Based Access Control (RBAC)

B.Attribute-Based Access Control (ABAC)

C.Discretionary Access Control (DAC)

D.Security Labels

E.Transformation Procedures (TPs)

AnswerE

TPs are the core of Clark-Wilson to ensure state transitions remain consistent.

Why this answer

Clark-Wilson uses Transformation Procedures (TPs) to move system state from one consistent state to another, strictly controlling access.

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MCQeasy

A developer is configuring a web application to use the principle of least privilege. Which action best aligns with this philosophy?

A.Granting the application access to all system environment variables.

B.Using a dedicated service account with granular permissions for database access.

C.Enabling 'Everyone' write access to application configuration files.

D.Running the application process as 'root' or 'administrator'.

AnswerB

This restricts the account to only the specific permissions needed for the task.

Why this answer

Least privilege requires granting only the minimum necessary permissions for a task.

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MCQmedium

When implementing the Biba Integrity Model, which operation is restricted for a subject to maintain the integrity of a higher-level object?

A.Read-up

B.Write-up

C.Execute-down

D.Read-down

E.Append-down

AnswerD

Read-down is prohibited to prevent a high-integrity subject from reading lower-integrity (less trusted) data.

Why this answer

Biba is the inverse of Bell-LaPadula, focusing on integrity. It prevents 'read-down' to ensure a process doesn't ingest corrupted data from a lower level.

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MCQeasy

What is the primary goal of the 'Principle of Least Privilege' (PoLP)?

A.To restrict access to the minimum necessary for a task.

B.To simplify administrative tasks by giving everyone full access.

C.To ensure that security controls are invisible to users.

D.To provide all users with the same set of permissions.

E.To automatically grant permissions based on time of day.

AnswerA

This limits the scope of potential compromise.

Why this answer

PoLP ensures that entities are granted only the minimum level of access required to perform their functions.

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MCQhard

A security team implements a 'Separation of Duties' policy in the CI/CD pipeline. Which implementation is correct?

A.One developer commits code, and a separate user with deployment permissions triggers the release.

B.The same developer writes, reviews, and deploys the code.

C.The QA team is allowed to modify production database records.

D.The build server automatically deploys code without human verification.

E.All developers have access to the production environment credentials.

AnswerA

This ensures two different roles are required to complete the task.

Why this answer

Separation of Duties prevents one person from having enough access to execute a malicious change without oversight.

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Multi-Selectmedium

Which TWO of the following are recognized components of the 'Confidentiality, Integrity, and Availability' (CIA) triad?

Select 2 answers

A.Non-repudiation

B.Accounting

C.Integrity

D.Confidentiality

E.Authentication

AnswersC, D

This is a core component.

Why this answer

The CIA triad consists of Confidentiality, Integrity, and Availability.

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MCQhard

You are using the 'Complete Mediation' principle in your system's access control design. What does this require?

A.Granting permanent access to all authenticated users.

B.Checking authorization only at login.

C.Checking authorization for every access request.

D.Relying on the user to request access when needed.

E.Caching permissions to reduce latency.

AnswerC

Every request must be checked against the policy.

Why this answer

Complete mediation requires that every access request to every object must be checked for authorization, with no caching or bypassing allowed.

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MCQmedium

You are designing a system to comply with 'Fail-Safe Defaults'. Which configuration best reflects this?

A.If the authorization check fails, explicitly deny the request.

B.If the authentication service is down, allow access to all users.

C.If the firewall fails, allow all traffic to pass through.

D.Default all new user accounts to 'Administrator' role.

E.If the load balancer times out, bypass the application logic.

AnswerA

This is 'fail-closed', which is a secure default.

Why this answer

Fail-safe defaults mean that if an error or crash occurs, the system defaults to the most secure state (e.g., access denied).

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MCQmedium

You are implementing 'Psychological Acceptability' in a new multi-factor authentication system. Which design choice is most appropriate?

A.Providing zero feedback to users during the login process.

B.Requiring a 64-character password changed every 24 hours.

C.Using a user-friendly mobile app push notification for authentication.

D.Disabling the ability for users to reset their own passwords.

E.Forcing users to solve a complex CAPTCHA at every login attempt.

AnswerC

This is easy and intuitive, increasing compliance.

Why this answer

Psychological acceptability ensures that security measures are easy for users to understand and use, so they don't circumvent them.

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Multi-Selecthard

When designing a secure API, which THREE of the following practices align with the principle of 'Defense-in-Depth'?

Select 3 answers

A.Encoding output to prevent XSS attacks in the browser.

B.Relying solely on the network firewall for all security.

C.Allowing all traffic through the API Gateway for performance.

D.Validating input within the application business logic layer.

E.Validating all incoming requests at the API Gateway level.

AnswersA, D, E

Layer 3 security.

Why this answer

Defense-in-depth uses multiple layers like input validation, authentication, and output encoding.

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MCQeasy

Which concept describes the ability of a system to provide services to authorized users even during a heavy load or denial of service attack?

A.Non-repudiation

B.Availability

C.Integrity

D.Authentication

E.Confidentiality

AnswerB

Availability ensures uptime and accessibility.

Why this answer

Availability specifically refers to the system's ability to remain operational and accessible.

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MCQmedium

A software architect is designing a system where data must remain accessible even if the primary database server fails. They implement a synchronous database replication strategy. Which core security concept is being prioritized?

A.Non-repudiation

B.Integrity

C.Availability

D.Confidentiality

AnswerC

Availability ensures systems and data are accessible when needed.

Why this answer

Availability is prioritized by ensuring data access despite server failure through replication.

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MCQmedium

When designing secure software, why is 'Economy of Mechanism' important?

A.To lower the cost of hardware infrastructure.

B.To minimize the attack surface by keeping the design simple.

C.To increase the lines of code for better functionality.

D.To ensure that the software is faster at runtime.

E.To enable easier debugging for developers.

AnswerB

Simplicity reduces the number of potential exploit vectors.

Why this answer

Economy of mechanism suggests that designs should be as simple and small as possible to minimize the attack surface and make security easier to verify.

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MCQeasy

Which of the following is an example of defense-in-depth in a web application architecture?

A.Disabling all firewall rules for testing purposes.

B.Storing all application data in a single encrypted volume.

C.Implementing input validation, parameterized queries, and a Web Application Firewall (WAF).

D.Removing all logs to prevent unauthorized access to audit trails.

E.Using a single strong password for all database accounts.

AnswerC

This provides multiple, independent layers of security against injection attacks.

Why this answer

Defense-in-depth uses multiple layers of security so that if one fails, others compensate.

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Multi-Selecteasy

Which TWO of the following actions support the 'Open Design' security principle?

Select 2 answers

A.Publishing the system architecture for security review.

B.Relying on standard, public cryptographic protocols like TLS.

C.Keeping the API endpoint documentation private.

D.Hiding the source code from all development team members.

E.Using a proprietary, secret encryption algorithm.

AnswersA, B

Transparency allows for peer review and finding flaws.

Why this answer

Open design suggests that security should not rely on the secrecy of the design or the algorithm itself (Kerckhoffs's principle).

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Multi-Selecteasy

Which TWO of the following are essential components for achieving 'Non-repudiation'?

Select 2 answers

A.Digital signatures

B.Immutable audit logs

C.Multi-factor authentication.

D.Load balancing.

E.Strong encryption of data in transit.

AnswersA, B

Provides proof of origin.

Why this answer

Non-repudiation requires proof of origin (usually via digital signature) and a secure, immutable audit trail.

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MCQeasy

A developer is performing a threat modeling exercise using STRIDE. What does the 'S' in STRIDE represent?

A.Software integrity

B.Service availability

C.System hardening

D.Secure architecture

E.Spoofing

AnswerE

Spoofing is the first category in the STRIDE threat model.

Why this answer

STRIDE stands for Spoofing, Tampering, Repudiation, Information disclosure, Denial of service, and Elevation of privilege.

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MCQhard

In an OAuth 2.0 flow, you are using the 'Authorization Code' grant type. You notice an attacker is attempting to intercept the code. Which security concept is being utilized by requiring the client_secret during the token exchange?

A.Availability

B.Non-repudiation

C.Confidentiality

D.Authentication

E.Integrity

AnswerD

Authentication verifies the identity of the client application.

Why this answer

The client_secret provides authentication of the client to the authorization server, ensuring only the intended client can exchange the code.

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Multi-Selecthard

In threat modeling, which THREE categories are explicitly defined by the STRIDE methodology?

Select 3 answers

A.Tampering

B.Repudiation

C.Encryption

D.Spoofing

E.Identification

AnswersA, B, D

This is a valid STRIDE category.

Why this answer

STRIDE categories are Spoofing, Tampering, Repudiation, Information disclosure, Denial of service, and Elevation of privilege.

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MCQmedium

A security auditor reviews your code and flags that you are using 'hardcoded cryptographic keys' in the source repository. Which security concept is being violated?

A.Availability

B.Confidentiality

C.Non-repudiation

D.Integrity

E.Accounting

AnswerB

Exposing keys in source code leads to a breach of secret material, violating confidentiality.

Why this answer

Hardcoded keys violate confidentiality because the keys are exposed to anyone with access to the source code.

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MCQmedium

Your application uses digital signatures to confirm the sender of a message. Which security goal is primarily achieved?

A.Authorization

B.Encryption

C.Availability

D.Non-repudiation

E.Confidentiality

AnswerD

A digital signature prevents a sender from denying the message origin.

Why this answer

Digital signatures are the standard mechanism for proving authenticity and non-repudiation.

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Multi-Selectmedium

Which TWO of the following are examples of how software can maintain 'Integrity'?

Select 2 answers

A.Encrypting data at rest using AES.

B.Ensuring the server is always online.

C.Using cryptographic hash functions (e.g., SHA-256) to verify file contents.

D.Implementing strong access control lists (ACLs) to prevent unauthorized writes.

E.Forcing users to change passwords regularly.

AnswersC, D

Hashes detect unauthorized changes.

Why this answer

Integrity is maintained through mechanisms that ensure data is not tampered with.

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Multi-Selecthard

When implementing a 'Zero Trust' architecture in software design, which THREE principles are fundamental?

Select 3 answers

A.Assume breach

B.Trust but verify

C.Use least privilege access

D.Trust all internal network traffic

E.Verify explicitly

AnswersA, C, E

Operate with the mindset that an attacker is already present.

Why this answer

Zero trust assumes no implicit trust and requires constant verification.

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MCQhard

You are applying the Bell-LaPadula model to a secure software system. A user with 'Secret' clearance attempts to write data to a 'Top Secret' file. Based on the *-property, what is the outcome?

A.The write is denied because the *-property prohibits writing to a higher security level.

B.The write is permitted.

C.The write is denied due to the no-write-down rule.

D.The system allows the write only if encryption is used.

AnswerA

The *-property prevents a user from writing to a higher level to prevent information flow leakage.

Why this answer

The *-property (star-property) of Bell-LaPadula prevents 'write-down', meaning a subject cannot write to a lower level, but also enforces no-read-up/no-write-down rules.

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