Remote DoS, or remote denial of service, is an attack or fault that makes a networked service or process stop working without requiring the attacker to be physically present on the target system. The result is usually a crash, hang, restart, or resource exhaustion that prevents normal operation.
In cyber security, remote DoS matters because availability is part of protection: if a scanner, gateway, or parser can be knocked offline, attackers may create blind spots even without taking control of the host. This often happens when a service processes attacker-controlled input, such as a file, archive, or network message, and a bug triggers a crash. Defenders look for resilient parsing, process isolation, rate limiting, health monitoring, and rapid patching so a failed component does not leave the environment unprotected.