CompTIA CAS-005 - CompTIA SecurityX Certification Exam

B. Pre-commit code linting: Linting tools analyze code for syntax errors andadherence to coding standards before the code is committed to the repository. This helps catch minor code issues early in the development process, reducing the likelihood of deployment failures.

D. Automated regression testing: Automated regression tests ensure that new code changes do not introduce bugs or regressions into the existing codebase. By running these tests automatically during the deployment process, developers can catch issues early and ensure the stability of the development environment.

Other options:

A. Software composition analysis: This helps identify vulnerabilities in third-party components but does not directly address code quality or deployment failures.

C. Repository branch protection: While this can help manage the code submission process, it does not directly prevent deployment failures caused by code issues or security check failures.

E. Code submit authorization workflow: This manages who can submit code but does not address the quality of the code being submitted.

F. Pipeline compliance scanning: This checks for compliance with security policies but does not address syntax or regression issues.

The first immediate action in an active incident iscontainment.Blocking the IP address (40.90.23.154)at the network edge prevents further communication with the malicious external server. Disabling PowerShell or removing local admin privileges are valid hardening steps, but containment by network control is the highest priority during an active compromise to stop data exfiltration or further command and control activity.

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.”

Geofencingallows the device to be restricted based on its physical location — disabling or locking devices when they move outside of trusted zones.Full disk encryptionensures that if a device is lost, the data remains inaccessible to unauthorized users. Containerization protects specific apps or data, but does not disable the entire device. Patch management, allow/blocklists, and geotagging serve other important functions but are not directly linked to the requirements in this scenario.

The best action to address the requirement of accessing the historian server within a SCADA system is to isolate the historian server for connections only from the SCADAenvironment. Here’s why:

Security and Isolation: Isolating the historian server ensures that only authorized devices within the SCADA environment can connect to it. This minimizes the attack surface and protects sensitive data from unauthorized access.

Access Control: By restricting access to the historian server to only SCADA devices, the organization can better control and monitor interactions, ensuring that only legitimate queries and data retrievals occur.

Best Practices for Critical Infrastructure: Following the principle of least privilege, isolating critical components like the historian server is a standard practice in securing SCADA systems, reducing the risk of cyberattacks.

For SSDs,incinerationis considered the most secure method of physical destruction, ensuring no data remanence. SSDs store data differently compared to traditional spinning disks, making degaussing ineffective. Overwriting and formatting may not reliably erase all storage cells due to wear-leveling technologies. Shredding may work if the granularity is extremely fine, but incineration guarantees complete destruction beyond recovery.

To mitigate the issue of excessive permissions and privilege creep, the best solutions are:

Implementing a Role-Based Access Policy:

Role-Based Access Control (RBAC): This policy ensures that access permissions are granted based on the user's role within the organization, aligning with the principle of least privilege. Users are only granted access necessary for their role, reducing the risk of excessive permissions.

The sshd_config file is the main configuration file for the OpenSSH server. To disable weak CBC (Cipher Block Chaining) ciphers for SSH connections, the security engineer should modify the sshd_config file to update the list of allowed ciphers. This file typically contains settings for the SSH daemon, including which encryption algorithms are allowed.

By editing the /etc/ssh/sshd_config file and updating the Ciphers directive, weak ciphers can be removed, and only strong ciphers can be allowed. This change ensures that the SSH server does not use insecure encryption methods.

The most secure way to prevent inadvertent data disclosure when encrypted SSDs are reused is to securely delete the encryption keys used by the SSD. Without the encryption keys, the data on the SSD remains encrypted and is effectively unreadable, rendering any residual data useless. This method is more reliable and efficient than overwriting data multiple times or using other physical destruction methods.