{
  "cveId": "CVE-2021-33620",
  "url": "https://patchblox.com/security/cve/CVE-2021-33620",
  "summary": "CVE-2021-33620 is fixed in 9 products on 1 platform, first by squid 3.5.27-1ubuntu1.11, released May 28, 2021. It is not reported as exploited. Patch Radar priority: High.",
  "title": "squid: Squid before 4.15 and 5.x before 5.0.6 allows remote servers to cause adenial of service (affecting availability to a...",
  "description": "Squid before 4.15 and 5.x before 5.0.6 allows remote servers to cause adenial of service (affecting availability to all clients) via an HTTPresponse. The issue trigger is a header that can be expected to exist inHTTP traffic without any malicious intent by the server.",
  "published": "2021-05-28T05:15:00Z",
  "severity": "Medium",
  "cvss": 7.4,
  "cvssVector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:N/A:H",
  "epss": 0.79583,
  "epssPercentile": 0.99607,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "libecap",
      "release": "RHEL 8",
      "fixedVersion": "0:1.0.1-2.module\u002Bel8.1.0\u002B4044\u002B36416a77",
      "fix": "RHSA-2021:4292",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2021-4292",
      "released": "2021-11-09T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libecap",
      "release": "almalinux 8",
      "fixedVersion": "1.0.1-2.module_el8.6.0\u002B2741\u002B01592ae8",
      "fix": "ALSA-2021:4292",
      "url": "https://patchblox.com/security/fix/linux/alsa-2021-4292",
      "released": "2021-11-09T08:56:14Z"
    },
    {
      "platform": "linux",
      "product": "libecap",
      "release": "ol 8",
      "fixedVersion": "0:1.0.1-2.module\u002Bel8.3.0\u002B7819\u002Beb7d4ef6",
      "fix": "ELSA-2021-4292",
      "url": "https://patchblox.com/security/fix/linux/elsa-2021-4292",
      "released": "2021-11-16T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libecap",
      "release": "rocky 8",
      "fixedVersion": "0:1.0.1-2.module\u002Bel8.4.0\u002B404\u002B316a0dc5",
      "fix": "RLSA-2021:4292",
      "url": "https://patchblox.com/security/fix/linux/rlsa-2021-4292",
      "released": "2021-11-09T08:56:14Z"
    },
    {
      "platform": "linux",
      "product": "libecap-devel",
      "release": "RHEL 8",
      "fixedVersion": "0:1.0.1-2.module\u002Bel8.1.0\u002B4044\u002B36416a77",
      "fix": "RHSA-2021:4292",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2021-4292",
      "released": "2021-11-09T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libecap-devel",
      "release": "almalinux 8",
      "fixedVersion": "1.0.1-2.module_el8.6.0\u002B2741\u002B01592ae8",
      "fix": "ALSA-2021:4292",
      "url": "https://patchblox.com/security/fix/linux/alsa-2021-4292",
      "released": "2021-11-09T08:56:14Z"
    },
    {
      "platform": "linux",
      "product": "libecap-devel",
      "release": "ol 8",
      "fixedVersion": "0:1.0.1-2.module\u002Bel8.3.0\u002B7819\u002Beb7d4ef6",
      "fix": "ELSA-2021-4292",
      "url": "https://patchblox.com/security/fix/linux/elsa-2021-4292",
      "released": "2021-11-16T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "squid",
      "release": "RHEL 8",
      "fixedVersion": "7:4.15-1.module\u002Bel8.5.0\u002B11469\u002B24c223d9",
      "fix": "RHSA-2021:4292",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2021-4292",
      "released": "2021-11-09T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "squid",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "3.5.27-1ubuntu1.11",
      "fix": "squid 3.5.27-1ubuntu1.11",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-squid-3.5.27-1ubuntu1.11",
      "released": "2021-05-28T05:15:00Z"
    },
    {
      "platform": "linux",
      "product": "squid",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "4.10-1ubuntu1.4",
      "fix": "squid 4.10-1ubuntu1.4",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-squid-4.10-1ubuntu1.4",
      "released": "2021-05-28T05:15:00Z"
    },
    {
      "platform": "linux",
      "product": "squid",
      "release": "Ubuntu 24.10 (oracular)",
      "fixedVersion": "4.13-10ubuntu1",
      "fix": "squid 4.13-10ubuntu1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-oracular-squid-4.13-10ubuntu1",
      "released": "2026-01-16T01:42:22Z"
    },
    {
      "platform": "linux",
      "product": "squid",
      "release": "Ubuntu 25.04 (plucky)",
      "fixedVersion": "4.13-10ubuntu1",
      "fix": "squid 4.13-10ubuntu1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-plucky-squid-4.13-10ubuntu1",
      "released": "2026-01-16T01:42:24Z"
    },
    {
      "platform": "linux",
      "product": "squid",
      "release": "almalinux 8",
      "fixedVersion": "7:4.15-3.module_el8.6.0\u002B3010\u002B383bc947.1",
      "fix": "ALSA-2021:4292",
      "url": "https://patchblox.com/security/fix/linux/alsa-2021-4292",
      "released": "2021-11-09T08:56:14Z"
    },
    {
      "platform": "linux",
      "product": "squid",
      "release": "ol 8",
      "fixedVersion": "7:4.15-1.module\u002Bel8.5.0\u002B20327\u002B24c223d9",
      "fix": "ELSA-2021-4292",
      "url": "https://patchblox.com/security/fix/linux/elsa-2021-4292",
      "released": "2021-11-16T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "squid",
      "release": "rocky 8",
      "fixedVersion": "7:4.15-1.module\u002Bel8.5.0\u002B705\u002B218dec94",
      "fix": "RLSA-2021:4292",
      "url": "https://patchblox.com/security/fix/linux/rlsa-2021-4292",
      "released": "2021-11-09T08:56:14Z"
    },
    {
      "platform": "linux",
      "product": "squid-cgi",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "3.5.27-1ubuntu1.11",
      "fix": "squid-cgi 3.5.27-1ubuntu1.11",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-squid-cgi-3.5.27-1ubuntu1.11",
      "released": "2021-05-28T05:15:00Z"
    },
    {
      "platform": "linux",
      "product": "squid-cgi",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "4.10-1ubuntu1.4",
      "fix": "squid-cgi 4.10-1ubuntu1.4",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-squid-cgi-4.10-1ubuntu1.4",
      "released": "2021-05-28T05:15:00Z"
    },
    {
      "platform": "linux",
      "product": "squid-cgi",
      "release": "Ubuntu 24.10 (oracular)",
      "fixedVersion": "4.13-10ubuntu1",
      "fix": "squid-cgi 4.13-10ubuntu1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-oracular-squid-cgi-4.13-10ubuntu1",
      "released": "2026-01-16T01:42:22Z"
    },
    {
      "platform": "linux",
      "product": "squid-cgi",
      "release": "Ubuntu 25.04 (plucky)",
      "fixedVersion": "4.13-10ubuntu1",
      "fix": "squid-cgi 4.13-10ubuntu1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-plucky-squid-cgi-4.13-10ubuntu1",
      "released": "2026-01-16T01:42:24Z"
    },
    {
      "platform": "linux",
      "product": "squid-common",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "3.5.27-1ubuntu1.11",
      "fix": "squid-common 3.5.27-1ubuntu1.11",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-squid-common-3.5.27-1ubuntu1.11",
      "released": "2021-05-28T05:15:00Z"
    },
    {
      "platform": "linux",
      "product": "squid-common",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "4.10-1ubuntu1.4",
      "fix": "squid-common 4.10-1ubuntu1.4",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-squid-common-4.10-1ubuntu1.4",
      "released": "2021-05-28T05:15:00Z"
    },
    {
      "platform": "linux",
      "product": "squid-common",
      "release": "Ubuntu 24.10 (oracular)",
      "fixedVersion": "4.13-10ubuntu1",
      "fix": "squid-common 4.13-10ubuntu1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-oracular-squid-common-4.13-10ubuntu1",
      "released": "2026-01-16T01:42:22Z"
    },
    {
      "platform": "linux",
      "product": "squid-common",
      "release": "Ubuntu 25.04 (plucky)",
      "fixedVersion": "4.13-10ubuntu1",
      "fix": "squid-common 4.13-10ubuntu1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-plucky-squid-common-4.13-10ubuntu1",
      "released": "2026-01-16T01:42:24Z"
    },
    {
      "platform": "linux",
      "product": "squid-openssl",
      "release": "Ubuntu 24.10 (oracular)",
      "fixedVersion": "4.13-10ubuntu1",
      "fix": "squid-openssl 4.13-10ubuntu1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-oracular-squid-openssl-4.13-10ubuntu1",
      "released": "2026-01-16T01:42:22Z"
    },
    {
      "platform": "linux",
      "product": "squid-openssl",
      "release": "Ubuntu 25.04 (plucky)",
      "fixedVersion": "4.13-10ubuntu1",
      "fix": "squid-openssl 4.13-10ubuntu1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-plucky-squid-openssl-4.13-10ubuntu1",
      "released": "2026-01-16T01:42:24Z"
    },
    {
      "platform": "linux",
      "product": "squid-purge",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "3.5.27-1ubuntu1.11",
      "fix": "squid-purge 3.5.27-1ubuntu1.11",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-squid-purge-3.5.27-1ubuntu1.11",
      "released": "2021-05-28T05:15:00Z"
    },
    {
      "platform": "linux",
      "product": "squid-purge",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "4.10-1ubuntu1.4",
      "fix": "squid-purge 4.10-1ubuntu1.4",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-squid-purge-4.10-1ubuntu1.4",
      "released": "2021-05-28T05:15:00Z"
    },
    {
      "platform": "linux",
      "product": "squid-purge",
      "release": "Ubuntu 24.10 (oracular)",
      "fixedVersion": "4.13-10ubuntu1",
      "fix": "squid-purge 4.13-10ubuntu1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-oracular-squid-purge-4.13-10ubuntu1",
      "released": "2026-01-16T01:42:22Z"
    },
    {
      "platform": "linux",
      "product": "squid-purge",
      "release": "Ubuntu 25.04 (plucky)",
      "fixedVersion": "4.13-10ubuntu1",
      "fix": "squid-purge 4.13-10ubuntu1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-plucky-squid-purge-4.13-10ubuntu1",
      "released": "2026-01-16T01:42:24Z"
    },
    {
      "platform": "linux",
      "product": "squid3",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "3.5.27-1ubuntu1.11",
      "fix": "squid3 3.5.27-1ubuntu1.11",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-squid3-3.5.27-1ubuntu1.11",
      "released": "2021-05-28T05:15:00Z"
    },
    {
      "platform": "linux",
      "product": "squidclient",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "3.5.27-1ubuntu1.11",
      "fix": "squidclient 3.5.27-1ubuntu1.11",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-squidclient-3.5.27-1ubuntu1.11",
      "released": "2021-05-28T05:15:00Z"
    },
    {
      "platform": "linux",
      "product": "squidclient",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "4.10-1ubuntu1.4",
      "fix": "squidclient 4.10-1ubuntu1.4",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-squidclient-4.10-1ubuntu1.4",
      "released": "2021-05-28T05:15:00Z"
    },
    {
      "platform": "linux",
      "product": "squidclient",
      "release": "Ubuntu 24.10 (oracular)",
      "fixedVersion": "4.13-10ubuntu1",
      "fix": "squidclient 4.13-10ubuntu1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-oracular-squidclient-4.13-10ubuntu1",
      "released": "2026-01-16T01:42:22Z"
    },
    {
      "platform": "linux",
      "product": "squidclient",
      "release": "Ubuntu 25.04 (plucky)",
      "fixedVersion": "4.13-10ubuntu1",
      "fix": "squidclient 4.13-10ubuntu1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-plucky-squidclient-4.13-10ubuntu1",
      "released": "2026-01-16T01:42:24Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-09T01:18:40Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}