CompTIA CAS-005 - CompTIA SecurityX Certification Exam

The table shows that the user "SALES1" is consistently blocked despite having met the MFA requirements. The common factor in these blocked attempts is the source IP address (8.11.4.16) being identified as from Germany while the user is assigned to France. This discrepancy suggests that the network geolocation is being misidentified by the authentication server, causing legitimate access attempts to be blocked.

Why Network Geolocation Misidentification?

Geolocation Accuracy: Authentication systems often use IP geolocation to verify the location of access attempts. Incorrect geolocation data can lead to legitimate requests being denied if they appear to come from unexpected locations.

Security Policies: Company security policies might block access attempts from certain locations to prevent unauthorized access. If the geolocation is wrong, legitimate users can be inadvertently blocked.

Consistent Pattern: The user "SALES1" from the IP address 8.11.4.16 is always blocked, indicating a consistent issue with geolocation.

Other options do not align with the pattern observed:

A. Bypass MFA requirements: MFA is satisfied, so bypassing MFA is not the issue.

C. Administrator access policy: This is about user access, not specific administrator access.

D. OTP codes: The user has satisfied MFA, so OTP code configuration is not the issue.

To ensure the most secure way of keeping a legacy system (COL) operating until a new solution is available, isolating the system and enforcing strict firewall rules is the best approach. This method minimizes the attack surface by restricting access to only the necessary endpoints, thereby reducing the risk of unauthorized access and potential security breaches. Isolating the system ensures that it is not exposed to the broader network, while firewall rules control the traffic that can reach the system, providing a secure environment until a replacement is implemented.

The code indicates that a WordPress (CMS) plug-in has likely been exploited. The function get_hex_cache() combines obfuscated PHP code (hex2bin) with external file retrieval (inc.tmp). This is characteristic of malicious plug-in injections in content management systems such as WordPress, where attackers inject backdoors or malicious scripts through vulnerable plug-ins.

Option B (search engine bots blocked) and C (corrupted stylesheet) would not explain injected PHP logic. Option D (WAF in transparent mode) reduces security controls but does not create malicious functions inside the CMS code.

The presence of obfuscated data in inc.tmp strongly suggests tampering. Exploited CMS plug-ins are a common initial access vector, often used to hide persistent malware or web shells.

This aligns with CAS-005 objectives on secure coding, monitoring for tampering, and conducting regular code reviews of third-party dependencies.

The key requirement is toinstantly eliminate data losson a lost device.

Cryptographic erasureworks by deleting encryption keys used for FDE (full disk encryption), rendering all data unrecoverable within seconds — satisfying the "mitigate within seconds" requirement.

Revoking certificates won’t wipe the data from a lost tablet.

Changing MFA credentials won’t help unless the device is secured, and app allow lists don’t apply post-loss.

FromCAS-005, Domain 3: Secure Systems Design and Deployment:

“Cryptographic erase (CE) renders data irrecoverable by deleting encryption keys used to protect data on the device.”

Animmutable databasepreventsmodifications or deletions, ensuring resilience against ransomware while maintaining multiple copies of data.

Implementing a Single Sign-On (SSO) solution and integrating it with applications is the best way to manage the situation and decrease risks. Here’s why:

Reduced Password Fatigue: SSO allows users tolog in once and gain access to multiple applications and systems without needing to remember and manage multiple passwords. This reduces the likelihood of users writing down passwords.

Improved Security: By reducing the number of passwords users need to manage, SSO decreases the attack surface and potential for password-related security breaches. It also allows for the implementation of stronger authentication methods.

User Convenience: SSO improves the user experience by simplifying the login process, which can lead to higher productivity and satisfaction.

Unauthorized code changesand lack ofindependent verificationare directly mitigated bycode signing, which ensures that code is from a trusted source and has not been altered.

While digital signatures are part of code signing, the broader practice of code signing encompasses signature management, version integrity, and trusted sources.

Lightweight cryptography is irrelevant in this context; it's more about efficiency in constrained devices.

Non-repudiation is a benefit of digital signatures but doesn't directly solve the verification/integrity concerns alone.

FromCAS-005 Guide, Domain 4: Security Architecture, Tools, and Technologies:

“Code signing ensures that the code has not been tampered with and originates from a trusted developer.”

The Center for Internet Security (CIS) Controls provide prescriptive best practices for validating and securing perimeter firewalls. These controls are specifically designed to offer detailed, actionable steps that organizations can follow to ensure firewall rules are configured properly, access is restricted to least privilege, and unnecessary services are disabled. CIS benchmarks also provide specific configuration guidance for different vendors, making them highly practical for real-world implementation and validation.

MITRE ATT&CK (B) is a framework for adversary tactics, techniques, and procedures, valuable for threat modeling but not a direct standard for firewall validation. NIST CSF (C) provides a high-level framework for cybersecurity risk management but lacks specific configuration guidance for firewalls. ISO 27001 (D) defines an information security management system (ISMS) framework, focusing on governance and certification rather than hands-on configuration best practices.

Therefore, the CIS Controls and Benchmarks represent the most direct and practical resource for validating firewall configurations in line with recognized industry best practices.