ISC Systems Security Implementation Verification And Validation — 10 Questions

Question 1

When validating the security implementation of a Cisco ASA firewall, which command provides the most accurate verification of the currently applied Access Control List (ACL) to a specific interface?

Accepted Answer

show access-list. While 'show access-list' displays all configured access lists and their hit counts, the 'show access-group' command (or examining the specific interface configuration via 'show run interface') is required to see which ACL is actually applied to a specific interface. However, looking at the standard Cisco ASA command set, to see the applied access groups, 'show access-group' is used. If sticking strictly to the provided options, 'show run interface' actually shows the applied access-group for that specific interface, making the current correct answer and explanation inaccurate for the specific wording of the question.

Answer

show run interface

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show version

Answer

show interface status

Question 2

A security engineer is validating the implementation of a TLS 1.3 configuration on an Nginx server. Which configuration directive must be verified to ensure only secure ciphers are used?

Accepted Answer

ssl_prefer_server_ciphers on;. To ensure that specific secure ciphers are used in Nginx, the 'ssl_ciphers' directive must be configured. Note that in TLS 1.3, cipher suites cannot be selected individually using 'ssl_ciphers' in older configurations in the same way as TLS 1.2, but 'ssl_ciphers' is the standard Nginx directive associated with cipher configuration.

Answer

ssl_session_cache shared:SSL:10m;

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ssl_verify_client on;

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ssl_protocols TLSv1.3;

Question 3

During a penetration test of a web application, you identify an insecure direct object reference (IDOR). What is the most effective way to verify that your remediation via access control checks is successful?

Accepted Answer

Execute automated authorization testing using a tool like Burp Suite Intruder to verify that non-authorized users receive a 403 Forbidden response.. Regression testing ensures that the fix addresses the vulnerability without breaking functionality.

Answer

Review the source code to ensure that the developer used a random UUID instead of sequential integers.

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Run a vulnerability scanner to check for OWASP Top 10 compliance.

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Perform a manual cross-site scripting (XSS) payload injection to confirm input sanitization.

Question 4

During a cloud security audit, you need to verify that IAM users do not have overly permissive policies. Which AWS feature provides automated validation of IAM policy adherence to least privilege?

Accepted Answer

AWS IAM Access Analyzer. AWS IAM Access Analyzer uses automated reasoning to analyze resource-based policies and IAM policies to identify resources that can be accessed from outside the account or identify unused permissions, which directly supports the principle of least privilege.

Answer

AWS Security Hub

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AWS CloudTrail

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AWS Trusted Advisor

Question 5

You are validating the security of a web service using OAuth 2.0. Which specific verification step ensures that the authorization code is not leaked?

Accepted Answer

Verify that the redirect_uri is strictly validated against a whitelist on the authorization server.. Strictly validating the 'redirect_uri' on the authorization server ensures that authorization codes are only sent to legitimate, pre-registered endpoints belonging to the client application, preventing attackers from registering malicious URIs to intercept or leak the code.

Answer

Check the HTTP header for 'X-Frame-Options'.

Answer

Verify that the client secret is stored in the database.

Answer

Ensure the application uses HTTPS.

Question 6

You are verifying the implementation of an Intrusion Detection System (IDS). Which technique is used to ensure the IDS is detecting traffic as expected?

Accepted Answer

Replay a known malicious packet capture (PCAP) through the network segment.. Simulated attacks (using tools like Metasploit or Nmap) are the only way to verify detection capability.

Answer

Review the last update date of the signature database.

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Check the IDS management console for 'Up' status.

Answer

Verify that the IDS is configured in 'Inline' mode.

Question 7

During a validation exercise, you need to confirm that an application's logging mechanism is compliant with NIST SP 800-92. Which element must be verified?

Accepted Answer

Ensure every log entry contains a user ID, timestamp, and event outcome.. NIST SP 800-92 emphasizes that logs must include user IDs, timestamps, and success/failure status.

Answer

Check if logs are printed to the console.

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Confirm that the logging level is set to 'DEBUG'.

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Verify that all logs are stored in a database.

Question 8

You are verifying the security configuration of an Amazon S3 bucket. Which S3 feature must be enabled to ensure that object deletions are reversible in case of accidental or malicious data loss?

Accepted Answer

S3 Object Lock. S3 Object Lock enables you to store objects using a 'Write Once, Read Many' (WORM) model. It helps prevent objects from being deleted or overwritten for a fixed amount of time or indefinitely, ensuring data loss protection against accidental or malicious deletions. While S3 Versioning keeps previous versions, a standard versioned object can still be permanently deleted by removing all versions or using a delete marker (unless MFA Delete is enabled). Object Lock provides the definitive safeguard against deletion.

Answer

S3 Block Public Access

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S3 Versioning

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S3 Lifecycle Policies

Question 9

You are validating the security of a web application. Which TWO of the following actions verify that input validation is effective against SQL injection?

Accepted Answer

Attempting to input common SQL injection characters (e.g., ') in application fields.. Using parameterized queries and reviewing input filter logic are the two most effective ways to verify SQLi defenses.

Answer

Verifying that the database administrator account has full system access.

Answer

Ensuring the website uses SSL/TLS for all traffic.

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Checking that the web server is running on the latest patch version.

Question 10

During a security audit of a PKI implementation, which TWO of the following must be verified to ensure the integrity of the certificate chain?

Accepted Answer

The Certificate Revocation List (CRL) is updated and accessible.. Option D is correct because a current, reachable CRL (or OCSP responder) is essential for chain integrity validation: relying parties must be able to confirm that no certificate in the chain has been revoked, and a stale or unreachable CRL breaks path validation and can cause clients to reject or improperly trust certificates. Option E is correct because the Root CA private key is the ultimate trust anchor for the entire chain; storing it in a FIPS 140-2/140-3 validated HSM with strict access controls and offline protection prevents key compromise, which would otherwise allow an attacker to forge certificates and invalidate the integrity of every chain. Option A is incorrect because serial numbers must be unique per issuer, not identical across all server certificates; duplicate serials would actually indicate a serious CA defect. Option B is incorrect because domain membership of the CA server is irrelevant to cryptographic chain integrity and is not required for a standalone or offline Root CA. Option C is incorrect because 1024-bit RSA is deprecated and weak; modern PKI requires at least 2048-bit RSA (or ECDSA P-256/P-384), so mandating 1024-bit keys would undermine, not ensure, integrity.

Answer

All server certificates have the same serial number.

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The CA server is joined to the domain.

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All certificates are issued with 1024-bit RSA keys.