Vulnerability · Published Feb 26, 2021 · Assigned by GitHub_M

CVE-2021-21328Denial of Service

Medium 5.3

In plain English

A medium-severity uncontrolled resource consumption in vapor from vapor. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.8% (higher than 79% of all known vulnerabilities).

Severity (CVSS 3.1)5.3Medium

Exploit odds (30 days)1.8%top 21.0% of all CVEs

Exploited in the wildNo reportsnot in CISA KEV

Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

Vendor	Product	Versions
vapor	vapor	<= 4.40.0

Weakness: CWE-400 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

References

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