= SQL injection is a type of attack that enables the use of an input field to run commands that can view or manipulate data in a database. SQL stands for Structured Query Language, which is a language used to communicate with databases. By injecting malicious SQL statements into an input field, an attacker can bypass authentication, access sensitive information, modify or delete data, or execute commands on the server. SQL injection is one of the most common and dangerous web application vulnerabilities. References = CompTIA Security+ Study Guide with over 500 Practice Test Questions: Exam SY0-701, 9th Edition, Chapter 5, page 195. CompTIA Security+ SY0-701 Exam Objectives, Domain 1.1, page 8.

In a cloud environment, high availability is typically ensured through the use of a load balancer. A load balancer distributes network or application traffic across multiple servers, ensuring that no single server becomes overwhelmed and that services remain available even if one or more servers fail. This setup enhances the reliability and availability of applications.
Load balancer: Ensures high availability by distributing traffic across multiple servers or instances, preventing overload and ensuring continuous availability.
Access broker: Typically refers to a service that facilitates secure access to resources, not directly related to high availability.
Cloud HSM (Hardware Security Module): Provides secure key management in the cloud but does not specifically ensure high availability.
WAF (Web Application Firewall): Protects web applications by filtering and monitoring HTTP traffic but is not primarily focused on ensuring high availability.

Compensating controls are alternative security measures that are implemented when the primary controls are not feasible, cost-effective, or sufficient to mitigate the risk. In this case, the organization used compensating controls to protect the legacy system from potential attacks by disabling unneeded services and placing a firewall in front of it. This reduced the attack surface and the likelihood of exploitation.

The security engineer is likely to deploy a Web Application Firewall (WAF) to protect the new web portal service. A WAF specifically protects web applications by filtering, monitoring, and blocking HTTP requests based on a set of rules. This is crucial for preventing common attacks such as SQL injection, cross-site scripting (XSS), and other web-based attacks that could compromise the web service.
* Layer 4 firewall operates primarily at the transport layer, focusing on IP address and port filtering, making it unsuitable for web application-specific threats.
* NGFW (Next-Generation Firewall) provides more advanced filtering than traditional firewalls, including layer 7 inspection, but the WAF is tailored specifically for web traffic.
* UTM (Unified Threat Management) offers a suite of security tools in one package (like antivirus, firewall, and content filtering), but for web application-specific protection, a WAF is the best fit.

Badge access and access control vestibule are two of the best ways to ensure only authorized personnel can access a secure facility. Badge access requires the personnel to present a valid and authenticated badge to a reader or scanner that grants or denies access based on predefined rules and permissions. Access control vestibule is a physical security measure that consists of a small room or chamber with two doors, one leading to the outside and one leading to the secure area. The personnel must enter the vestibule and wait for the first door to close and lock before the second door can be opened. This prevents tailgating or piggybacking by unauthorized individuals.