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Secure Software Architecture And DesignhardMultiple ChoiceObjective-mapped

CSSLP Secure Software Architecture And Design Practice Question

You are auditing a design that uses JSON Web Tokens (JWTs) for stateless authentication. Which vulnerability is most critical if the 'alg: none' attack is possible?

Answer choices

Why each option matters

Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.

Correct answer & explanation

Token signature bypass/forgery.

The 'alg: none' vulnerability allows an attacker to forge tokens by telling the server to skip signature verification.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

  • Cross-Site Request Forgery (CSRF).

    Why it's wrong here

    CSRF is a session-based vulnerability, not a token forging issue.

  • Broken object-level authorization.

    Why it's wrong here

    This is a logic error, not a token verification error.

  • Insecure cookie flags.

    Why it's wrong here

    JWTs are often stored in local storage, not just cookies.

  • Token signature bypass/forgery.

    Why this is correct

    An attacker can manipulate claims in the token without the server detecting the change.

About these practice questions

One of 198 original CSSLP practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →

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JA

Written and reviewed by Johnson Ajibi, MSc IT Security

Senior Network & Security Engineer · founder of Courseiva

Last reviewed August 2026 · checked against the official (ISC)² exam blueprint

This CSSLP practice question is part of Courseiva's free (ISC)² certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the CSSLP exam.