SecurityX CAS-005 CompTIA Study Notes

For a disaster recovery (DR) plan requiring immediate data availability, the first step is understanding what needs to be protected and recovered. Identifying critical business processes and their associated software and hardware requirements establishes the foundation for the DR plan. This ensures that backups and recovery mechanisms align with business priorities, meeting the "moment's notice" requirement.

Option A:A change management plan is important for system consistency but doesn’t directly address immediate data availability in a DR context.

Option B:Hiring staff supports execution but doesn’t define what needs to be recovered or how. It’s a later step.

Option C:A warm site (a partially operational backup site) is a good DR solution, but designing it comes after identifying critical processes and resources.

Option D:This is the first step in any DR planning process—knowing what’s critical ensures the plan meets availability goals efficiently.

Comprehensive and Detailed Explanation:

The log shows an AXFR (zone transfer) query, which exposed internal DNS records, aiding lateral movement. Let’s evaluate:

A. Disabling DNS zone transfers:AXFR allows full DNS zone data to be transferred. Disabling it externally prevents attackers from mapping internal networks, directly mitigating this issue per CAS-005’s security operations focus.

B. Restricting to UDP/53:AXFR uses TCP/53, so this wouldn’t stop it.

C. DNS masking:Obscures records but isn’t a standard term for this fix.

The output shows that multiple systems have outdated or vulnerable software versions (OpenSSL 1.01 and Java 11 runtime). This suggests that the systems are not being patched regularly or effectively.

A. Automating the patching system to update base images: Automating the patching process ensures that the latest security updates and patches are applied to all systems, including newly deployed ones. This addresses the root cause by ensuring that base images used for deployment are always up-to-date with the latest security patches.

B. Recompiling the affected programs with the most current patches: While this can fix the immediate vulnerabilities, it does not address the root cause of the problem, which is the lack of regular updates.

C. Disabling unused/unneeded ports on all servers: This improves security but does not address the specific issue of outdated software.

D. Deploying a WAF with virtual patching upstream of the affected systems: This can provide a temporary shield but does not resolve the underlying issue of outdated software.

Automating the patching system to update base images ensures that all deployed systems are using the latest, most secure versions of software, addressing the root cause of the vulnerability trend.

The scenario describes a sophisticated attack where the threat actor used steganography within LDAP to exfiltrate data. Given that the hardware and OS firmware were validated and found uncompromised, the attack vector likely exploited a network communication channel. To mitigate such risks, enforcing allow lists for authorized network ports and protocols is the most effective strategy.

Here’s why this option is optimal:

Port and Protocol Restrictions: By creating an allow list, the organization can restrict communications to only those ports and protocols that are necessary for legitimate business operations. This reduces the attack surface by preventing unauthorized or unusual traffic.

Network Segmentation: Enforcing such rules helps in segmenting the network and ensuring that only approved communications occur, which is critical in preventing data exfiltration methods like steganography.

Preventing Unauthorized Access: Allow lists ensure that only predefined, trusted connections are allowed, blocking potential paths that attackers could use to infiltrate or exfiltrate data.

Other options, while beneficial in different contexts, are not directly addressing the network communication threat:

B. Measuring and attesting to the entire boot chain: While this improves system integrity, it doesn’t directly mitigate the risk of data exfiltration through network channels.

C. Rolling the cryptographic keys used for hardware security modules: This is useful for securing data and communications but doesn’t directly address the specific method of exfiltration described.

D. Using code signing to verify the source of OS updates: Ensures updates are from legitimate sources, but it doesn’t mitigate the risk of network-based data exfiltration.