A distributed denial of service (DDoS) attack renders the customer's cloud inaccessible for 24 hours is an example of availability technical impact. Availability is the protection of data and services from disruption or denial, and it is one of the three dimensions of information security, along with confidentiality and integrity.
Availability technical impact refers to the extent of damage or harm that a threat can cause to the availability of the information system and its components, such as servers, networks, applications, and data. A DDoS attack is a malicious attempt to overwhelm a target system with a large volume of traffic or requests from multiple sources, making it unable to respond to legitimate requests or perform its normal functions. A DDoS attack can cause a significant availability technical impact by rendering the customer's cloud inaccessible for a prolonged period of time, resulting in loss of productivity, revenue, customer satisfaction, and reputation. References := CCAK Study Guide, Chapter 4: A Threat Analysis Methodology for Cloud Using CCM, page 81; What is a DDoS Attack? | Cloudflare