GCIH Exploiting Insecure Web App References Practice Question
An incident handler investigates a web application breach where an authenticated user modified a hidden form parameter containing an integer account ID, successfully viewing financial records belonging to other customers. Which underlying vulnerability class allowed this unauthorized data access?
⚠ Common exam trap
Candidates often confuse Insecure Direct Object References with Parameter Tampering, missing that parameter tampering is merely the attack mechanism rather than the architectural vulnerability allowing unauthorized access.
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
✓
Insecure Direct Object References resulting from missing authorization checks on object identifiers
Insecure Direct Object References occur when an application provides direct access to objects based on user-supplied input without verifying authorization. Attackers manipulate parameter values to access unauthorized resources, bypassing access controls entirely. Identifying this root cause is critical during incident response to properly scope data exposure, remediate broken access controls across the application architecture, and implement centralized authorization checks.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
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Cross-Site Scripting via unsanitized parameter reflection in hidden inputs
Why it's wrong here
Cross-Site Scripting involves injecting malicious scripts into web pages viewed by other users, which does not explain how altering an account ID parameter grants unauthorized data access to private financial records. This vulnerability stems from output handling rather than authorization logic flaws.
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Broken Authentication due to predictable session identifier generation
Why it's wrong here
Predictable session identifiers allow session hijacking rather than targeted horizontal privilege escalation via modified numeric parameters. The user was properly authenticated, but the application failed to verify if that specific user owned the requested account resource.
- ✓
Insecure Direct Object References resulting from missing authorization checks on object identifiers
Why this is correct
The application trusts the client-supplied account ID without verifying that the authenticated user owns that object, so tampering with the hidden parameter returns other customers' records. Authorisation must be enforced server-side against the session identity, not the submitted identifier.
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SQL Injection allowing arbitrary query execution via unsanitized numerical inputs
Why it's wrong here
SQL injection exploits improper handling of database queries rather than direct object reference failures. While the parameter value is numerical, successful exploitation yields database errors or data dumps rather than clean traversal of distinct user records.
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JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official GIAC exam blueprint
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