Vulnerability Database
296,733
Total vulnerabilities in the database
CVE-2021-29509
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.
| Software | From | Fixed in |
|---|---|---|
| puma / puma | 5.0.0 | 5.3.1 |
| puma / puma | - | 4.3.8 |
| debian / debian_linux | 10.0 | 10.0.x |
puma
|
- | 4.3.8 |
|
puma
|
5.0.0 | 5.3.1 |
- https://gist.github.com/nateberkopec/4b3ea5676c0d70cbb37c82d54be25837
- https://github.com/puma/puma/security/advisories/GHSA-q28m-8xjw-8vr5
- https://github.com/puma/puma/security/policy
- https://lists.debian.org/debian-lts-announce/2022/08/msg00015.html
- https://rubygems.org/gems/puma
- https://security.gentoo.org/glsa/202208-28
Deep Security Visibility Without the Complexity
SynScan provides clear, real-time security insights so you can monitor your attack surface, spot risks early, and act fast—without extra complexity.
- No setup fees
- 5-min deployment
- Cancel anytime