CVE-2021-29509
Assigner: GitHub_M
Published: 2021-05-11T16:50:11
State: PUBLISHED
affected: product: puma
vendor: puma
versions: status: affected
version: < 4.3.8
status: affected
version: >= 5.0.0, < 5.3.1
descriptions: value: Puma is a concurrent HTTP 1.1 server for Ruby/Rack applications. The fix for CVE-2019-16770 was incomplete. The original fix only protected existing connections that had already been accepted from having their requests starved by greedy persistent-connections saturating all threads in the same process. However, new connections may still be starved by greedy persistent-connections saturating all threads in all processes in the cluster. A `puma` server which received more concurrent `keep-alive` connections than the server had threads in its threadpool would service only a subset of connections, denying service to the unserved connections. This problem has been fixed in `puma` 4.3.8 and 5.3.1. Setting `queue_requests false` also fixes the issue. This is not advised when using `puma` without a reverse proxy, such as `nginx` or `apache`, because you will open yourself to slow client attacks (e.g. slowloris). The fix is very small and a git patch is available for those using unsupported versions of Puma.
metrics: cvssV3_1: attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: HIGH
baseScore: 7.5
baseSeverity: HIGH
confidentialityImpact: NONE
integrityImpact: NONE
privilegesRequired: NONE
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
version: 3.1
problemTypes: descriptions: cweId: CWE-400
description: CWE-400: Uncontrolled Resource Consumption
type: CWE
source: advisory: GHSA-q28m-8xjw-8vr5
discovery: UNKNOWN
title: Keepalive Connections Causing Denial Of Service in puma