Spin is the developer tool for building and running serverless applications powered by WebAssembly. Prior to 2.4.3, some specifically configured Spin applications that use `self` requests without a specified URL authority can be induced to make requests to arbitrary hosts via the `Host` HTTP header. The following conditions need to be met for an application to be vulnerable: 1. The environment Spin is deployed in routes requests to the Spin runtime based on the request URL instead of the `Host` header, and leaves the `Host` header set to its original value; 2. The Spin application\'s component handling the incoming request is configured with an `allow_outbound_hosts` list containing `"self"`; and 3. In reaction to an incoming request, the component makes an outbound request whose URL doesn\'t include the hostname/port. Spin 2.4.3 has been released to fix this issue.
Metrics
CVSS Version: 3.1 |
Base Score: 9.1 CRITICAL Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N