{
  "GSD": {
    "alias": "CVE-2021-29509",
    "description": "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.",
    "id": "GSD-2021-29509",
    "references": [
      "https://www.suse.com/security/cve/CVE-2021-29509.html",
      "https://access.redhat.com/errata/RHSA-2021:4702"
    ]
  },
  "gsd": {
    "metadata": {
      "exploitCode": "unknown",
      "remediation": "unknown",
      "reportConfidence": "confirmed",
      "type": "vulnerability"
    },
    "osvSchema": {
      "affected": [
        {
          "package": {
            "ecosystem": "RubyGems",
            "name": "puma",
            "purl": "pkg:gem/puma"
          }
        }
      ],
      "aliases": [
        "CVE-2021-29509",
        "GHSA-q28m-8xjw-8vr5"
      ],
      "details": "### Impact\n\nThe fix for CVE-2019-16770 was incomplete. The original fix only protected\nexisting connections that had already been accepted from having their\nrequests starved by greedy persistent-connections saturating all threads in\nthe same process. However, new connections may still be starved by greedy\npersistent-connections saturating all threads in all processes in the\ncluster.\n\nA puma server which received more concurrent keep-alive connections than the\nserver had threads in its threadpool would service only a subset of\nconnections, denying service to the unserved connections.\n\n### Patches\n\nThis problem has been fixed in puma 4.3.8 and 5.3.1.\n\n### Workarounds\n\nSetting queue_requests false also fixes the issue. This is not advised when\nusing puma without a reverse proxy, such as nginx or apache, because you will\nopen yourself to slow client attacks (e.g. [slowloris][1]).\n\nThe fix is very small. [A git patch is available here][2] for those using\n[unsupported versions][3] of Puma.\n\n[1]: https://en.wikipedia.org/wiki/Slowloris_(computer_security)\n[2]: https://gist.github.com/nateberkopec/4b3ea5676c0d70cbb37c82d54be25837\n[3]: https://github.com/puma/puma/security/policy#supported-versions",
      "id": "GSD-2021-29509",
      "modified": "2021-05-11T00:00:00.000Z",
      "published": "2021-05-11T00:00:00.000Z",
      "references": [
        {
          "type": "WEB",
          "url": "https://github.com/puma/puma/security/advisories/GHSA-q28m-8xjw-8vr5"
        }
      ],
      "related": [
        "CVE-2019-16770"
      ],
      "schema_version": "1.4.0",
      "severity": [
        {
          "score": 7.5,
          "type": "CVSS_V3"
        }
      ],
      "summary": "Keepalive Connections Causing Denial Of Service in puma"
    }
  },
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            "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."
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        "discovery": "UNKNOWN"
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      "cve": "2021-29509",
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      "date": "2021-05-11",
      "description": "### Impact\n\nThe fix for CVE-2019-16770 was incomplete. The original fix only protected\nexisting connections that had already been accepted from having their\nrequests starved by greedy persistent-connections saturating all threads in\nthe same process. However, new connections may still be starved by greedy\npersistent-connections saturating all threads in all processes in the\ncluster.\n\nA puma server which received more concurrent keep-alive connections than the\nserver had threads in its threadpool would service only a subset of\nconnections, denying service to the unserved connections.\n\n### Patches\n\nThis problem has been fixed in puma 4.3.8 and 5.3.1.\n\n### Workarounds\n\nSetting queue_requests false also fixes the issue. This is not advised when\nusing puma without a reverse proxy, such as nginx or apache, because you will\nopen yourself to slow client attacks (e.g. [slowloris][1]).\n\nThe fix is very small. [A git patch is available here][2] for those using\n[unsupported versions][3] of Puma.\n\n[1]: https://en.wikipedia.org/wiki/Slowloris_(computer_security)\n[2]: https://gist.github.com/nateberkopec/4b3ea5676c0d70cbb37c82d54be25837\n[3]: https://github.com/puma/puma/security/policy#supported-versions",
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      "related": {
        "cve": [
          "2019-16770"
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      "title": "Keepalive Connections Causing Denial Of Service in puma",
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    },
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          "cwe_ids": [
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          "date": "2022-10-27",
          "description": "Puma is a concurrent HTTP 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.",
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          "identifier": "CVE-2021-29509",
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          "not_impacted": "",
          "package_slug": "gem/gitlab-puma",
          "pubdate": "2021-05-11",
          "solution": "Unfortunately, there is no solution available yet.",
          "title": "Uncontrolled Resource Consumption",
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      "lastModifiedDate": "2022-10-27T12:39Z",
      "publishedDate": "2021-05-11T17:15Z"
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}