CVE-2021-29509

描述

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.

如何修補 CVE-2021-29509

要修補 CVE-2021-29509,請將受影響套件升級到下列已修補版本。

• —升級至 4.3.8 或更新版本

CVE-2021-29509 正在被利用嗎?

低 — EPSS 為 1.6%,目前沒有觀察到大規模利用活動。

受影響套件(1)

• from 0, < 4.3.8

CVSS 分數

參考連結(9)

• ADVISORYnvd.nist.gov/vuln/detail/CVE-2021-29509
• PATCHgithub.com/puma/puma
• WEBgist.github.com/nateberkopec/4b3ea5676c0d70cbb37c82d54be25837
• WEBgithub.com/puma/puma/security/advisories/GHSA-q28m-8xjw-8vr5
• WEB