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.
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History
No history.
MITRE
Status: PUBLISHED
Assigner: GitHub_M
Published: 2021-05-11T16:50:11
Updated: 2024-08-03T22:11:05.438Z
Reserved: 2021-03-30T00:00:00
Link: CVE-2021-29509
Vulnrichment
No data.
NVD
Status : Modified
Published: 2021-05-11T17:15:07.627
Modified: 2024-11-21T06:01:16.570
Link: CVE-2021-29509
Redhat