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CVE-2019-16770

Status: ModifiedHigh (7.5)—

In Puma before versions 3.12.2 and 4.3.1, a poorly-behaved client could use keepalive requests to monopolize Puma's reactor and create a denial of service attack. If more keepalive connections to Puma are opened than there are threads available, additional connections will wait permanently if the attacker sends requests frequently enough. This vulnerability is patched in Puma 4.3.1 and 3.12.2.

CVSS

Exploitation probability (EPSS)

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

Affected technologies (2)

Debian — Debian LinuxPuma — Puma

CWEs

References

Raw JSON (NVD)

Show
{
  "id": "CVE-2019-16770",
  "cveTags": [],
  "metrics": {
    "cvssMetricV2": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "version": "2.0",
          "baseScore": 5,
          "accessVector": "NETWORK",
          "vectorString": "AV:N/AC:L/Au:N/C:N/I:N/A:P",
          "authentication": "NONE",
          "integrityImpact": "NONE",
          "accessComplexity": "LOW",
          "availabilityImpact": "PARTIAL",
          "confidentialityImpact": "NONE"
        },
        "acInsufInfo": false,
        "impactScore": 2.9,
        "baseSeverity": "MEDIUM",
        "obtainAllPrivilege": false,
        "exploitabilityScore": 10,
        "obtainUserPrivilege": false,
        "obtainOtherPrivilege": false,
        "userInteractionRequired": false
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          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
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          "userInteraction": "NONE",
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          "integrityImpact": "NONE",
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  "published": "2019-12-05T20:15:10.093",
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  "vulnStatus": "Modified",
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      "description": [
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    {
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      "description": [
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  "descriptions": [
    {
      "lang": "en",
      "value": "In Puma before versions 3.12.2 and 4.3.1, a poorly-behaved client could use keepalive requests to monopolize Puma's reactor and create a denial of service attack. If more keepalive connections to Puma are opened than there are threads available, additional connections will wait permanently if the attacker sends requests frequently enough. This vulnerability is patched in Puma 4.3.1 and 3.12.2."
    },
    {
      "lang": "es",
      "value": "En Puma, anterior a las versiones 3.12.2 y 4.3.1, un cliente con mal comportamiento podría utilizar solicitudes de keepalive para monopolizar el reactor de Puma y crear un ataque de denegación de servicio. Si se abren más conexiones keepalive a Puma que hilos disponibles, las conexiones adicionales esperarán permanentemente si el atacante envía solicitudes con la suficiente frecuencia. Esta vulnerabilidad está reparada en Puma 4.3.1 y 3.12.2."
    }
  ],
  "lastModified": "2026-06-17T02:22:45.997",
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