CVE-2021-21328

Denial of Service

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.

Category

5.3
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.44%
Third-Party Advisory github.com Third-Party Advisory github.com Third-Party Advisory github.com
Affected: vapor vapor
Published at:
Updated at:

References

Frequently Asked Questions

What is the severity of CVE-2021-21328?
CVE-2021-21328 has been scored as a medium severity vulnerability.
How to fix CVE-2021-21328?
To fix CVE-2021-21328, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-21328 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-21328 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-21328?
CVE-2021-21328 affects vapor vapor.
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