CVE-2021-21328 Information

Description

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 for to vapor_route_undefined to avoid unlimited counters.

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Reference

https://github.com/vapor/vapor/releases/tag/4.40.1 https://github.com/vapor/vapor/commit/e3aa712508db2854ac0ab905696c65fd88fa7e23 https://github.com/vapor/vapor/security/advisories/GHSA-gcj9-jj38-hwmc https://vapor.codes/

Attack Complexity

LOW

Privileges Required

NONE

User Interaction Required

NONE

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

NONE

Availability Impact

NONE

Base Score

LOW

Base Severity

5.3