Which element of STRIDE deals with the risk of data availability loss?

The element of STRIDE that deals with the risk of data availability loss is Denial of Service. This threat model component focuses specifically on the potential harm caused by attacks that aim to make a service, application, or data unavailable to users. A Denial of Service (DoS) attack can overwhelm a server, network, or application with excessive requests, rendering it incapable of responding to legitimate requests. The impact of such attacks directly leads to data being inaccessible when needed, thus compromising availability.

In contrast, the other elements of STRIDE address different types of threats: Escalation of Privilege pertains to unauthorized users gaining higher levels of access, Information Disclosure revolves around unauthorized access to sensitive data, and Spoofing relates to impersonating another entity. While these are significant security concerns, they do not specifically emphasize the aspect of availability loss as Denial of Service does.