{
  "cveId": "CVE-2021-28651",
  "url": "https://patchblox.com/security/cve/CVE-2021-28651",
  "summary": "CVE-2021-28651 is fixed in 8 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: An issue was discovered in Squid before 4.15 and 5.x before 5.0.6",
  "description": "An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. Due to a buffer-management bug, it allows a denial of service. When resolving a request with the urn: scheme, the parser leaks a small amount of memory. However, there is an unspecified attack methodology that can easily trigger a large amount of memory consumption.",
  "published": "2021-05-27T05:15:00Z",
  "severity": "Medium",
  "cvss": 7.4,
  "epss": 0.0745,
  "epssPercentile": 0.94506,
  "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": "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-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": "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": "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-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-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-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": "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"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-11T01:43:54Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}