Vulnerability-Lookup

OESA-2021-1203 (CVE-2021-29509)

Vulnerability from osv_openeuler – Published: 2021-06-07 11:04 – Updated: 2026-08-06 11:04 – Source website

Summary

rubygem-puma security update

Details

A simple, fast, threaded, and highly concurrent HTTP 1.1 server for Ruby/Rack applications.

Security Fix(es):

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.(CVE-2021-29509)

Severity

7.5 (High)


                    
                      CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

URL

Type

	https://openeuler.org/en/security/safety-bulletin…	ADVISORY
	https://nvd.nist.gov/vuln/detail/CVE-2021-29509	ADVISORY

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "aarch64": [
          "rubygem-puma-3.12.6-2.oe1.aarch64.rpm",
          "rubygem-puma-debugsource-3.12.6-2.oe1.aarch64.rpm",
          "rubygem-puma-debuginfo-3.12.6-2.oe1.aarch64.rpm"
        ],
        "noarch": [
          "rubygem-puma-doc-3.12.6-2.oe1.noarch.rpm"
        ],
        "src": [
          "rubygem-puma-3.12.6-2.oe1.src.rpm"
        ],
        "x86_64": [
          "rubygem-puma-debugsource-3.12.6-2.oe1.x86_64.rpm",
          "rubygem-puma-3.12.6-2.oe1.x86_64.rpm",
          "rubygem-puma-debuginfo-3.12.6-2.oe1.x86_64.rpm"
        ]
      },
      "package": {
        "ecosystem": "openEuler:20.03-LTS-SP1",
        "name": "rubygem-puma",
        "purl": "pkg:rpm/openEuler/rubygem-puma\u0026distro=openEuler-20.03-LTS-SP1"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.12.6-2.oe1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "severity": "High"
  },
  "details": "A simple, fast, threaded, and highly concurrent HTTP 1.1 server for Ruby/Rack applications.\r\n\r\nSecurity Fix(es):\r\n\r\nPuma 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.(CVE-2021-29509)",
  "id": "OESA-2021-1203",
  "modified": "2026-08-06T11:04:26Z",
  "published": "2021-06-07T11:04:26Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://openeuler.org/en/security/safety-bulletin/detail.html?id=openEuler-SA-2021-1203"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-29509"
    }
  ],
  "schema_version": "1.7.2",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "rubygem-puma security update",
  "upstream": [
    "CVE-2021-29509"
  ]
}

CVE-2021-29509 (GCVE-0-2021-29509)

Vulnerability from cvelistv5 – Published: 2021-05-11 16:50 – Updated: 2024-08-03 22:11

Title

Keepalive Connections Causing Denial Of Service in puma

Summary

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.

Severity

7.5 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CWE

CWE-400 - {"CWE-400":"Uncontrolled Resource Consumption"}

Assigner

GitHub_M mitre root

References

6 references

URL	Tags
https://github.com/puma/puma/security/advisories/…	x_refsource_CONFIRM
https://gist.github.com/nateberkopec/4b3ea5676c0d…	x_refsource_MISC
https://github.com/puma/puma/security/policy	x_refsource_MISC
https://rubygems.org/gems/puma	x_refsource_MISC
https://security.gentoo.org/glsa/202208-28	vendor-advisoryx_refsource_GENTOO
https://lists.debian.org/debian-lts-announce/2022…	mailing-listx_refsource_MLIST

Impacted products

1 product

Vendor	Product	Version
puma	puma	Affected: < 4.3.8 Affected: >= 5.0.0, < 5.3.1

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
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          "dateUpdated": "2024-08-03T22:11:05.438Z",
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            "url": "https://github.com/puma/puma/security/policy"
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            "url": "https://rubygems.org/gems/puma"
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              "x_transferred"
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            "url": "https://lists.debian.org/debian-lts-announce/2022/08/msg00015.html"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "puma",
          "vendor": "puma",
          "versions": [
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        }
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      "metrics": [
        {
          "cvssV3_1": {
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            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
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      "references": [
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          "url": "https://rubygems.org/gems/puma"
        },
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}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.