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Uncontrolled Resource Consumption

CVE-2021-21328

Severity Medium
Score 5.3/10

Summary

Vapor is a web framework for Swift. In Vapor before version 4.40.1, there is a DoS attack against anyone who Bootstraps a metrics backend for their Vapor app. The following is the attack vector: 1. send unlimited requests against a vapor instance with different paths. this will create unlimited counters and timers, which will eventually drain the system. 2. downstream services might suffer from this attack as well by being spammed with error paths. This has been patched in 4.40.1. The `DefaultResponder` will rewrite any undefined route paths to `vapor_route_undefined` to avoid unlimited counters.

  • LOW
  • NETWORK
  • NONE
  • UNCHANGED
  • NONE
  • NONE
  • NONE
  • LOW

CWE-400 - Uncontrolled resource consumption

An uncontrolled resource allocation attack (also known as resource exhaustion attack) triggers unauthorized overconsumption of the limited resources in an application, such as memory, file system storage, database connection pool entries, and CPU. This may lead to denial of service for valid users and degradation of the application's functionality as well as that of the host operating system.

Advisory Timeline

  • Published