A Denial of Service (DoS) attack is specifically designed to degrade or deny service availability to legitimate users — by flooding a target with traffic or exhausting its resources, it causes large response delays, dropped requests/excessive losses, and outright service interruptions. That directly matches the description given. Eavesdropping attacks are passive information-gathering (sniffing traffic) and don't inherently degrade availability. Path traversal attacks exploit file-path handling to access unauthorized files/directories — a confidentiality/integrity issue, not primarily an availability one. URL tampering manipulates URL parameters to gain unauthorized access or alter behavior, again not primarily about causing delays/service loss. Only DoS is defined by its impact on availability as described.