Distributed Denial of Service (DDoS) attacks primarily impactavailability, one of the three pillars of the CIA triad. DDoS attacks overwhelm systems, networks, or applications with massive volumes of traffic, exhausting resources such as bandwidth, CPU, or memory and preventing legitimate users from accessing services.
The goal of a DDoS attack is not to steal data, alter information, or deny accountability, but rather todisrupt access. Confidentiality and integrity may remain intact, but users are unable to reach the system, resulting in service outages, financial loss, and reputational damage.
Availability is a critical security objective for public-facing services such as websites, APIs, and online platforms. Defenses against DDoS attacks include traffic filtering, rate limiting, content delivery networks (CDNs), scrubbing services, and redundant architectures.
Security frameworks such as NIST and ISO/IEC explicitly associate denial-of-service attacks with availability risks, making availability the most directly affected cybersecurity principle.