{
  "cveId": "CVE-2021-4209",
  "url": "https://patchblox.com/security/cve/CVE-2021-4209",
  "summary": "CVE-2021-4209 is fixed in 7 products on 1 platform, first by gnutls-bin 3.5.18-1ubuntu1.6, released August 1, 2022. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "gnutls28: A NULL pointer dereference flaw was found in GnuTLS",
  "description": "A NULL pointer dereference flaw was found in GnuTLS. As Nettle\u0027s hash update functions internally call memcpy, providing zero-length input may cause undefined behavior. This flaw leads to a denial of service after authentication in rare circumstances.",
  "published": "2022-02-22T12:07:00Z",
  "severity": "medium",
  "cvss": 6.5,
  "cvssVector": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
  "epss": 0.01908,
  "epssPercentile": 0.79888,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "gnutls-bin",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "3.5.18-1ubuntu1.6",
      "fix": "gnutls-bin 3.5.18-1ubuntu1.6",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-gnutls-bin-3.5.18-1ubuntu1.6",
      "released": "2022-08-01T07:15:00Z"
    },
    {
      "platform": "linux",
      "product": "gnutls-bin",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "3.6.13-2ubuntu1.7",
      "fix": "gnutls-bin 3.6.13-2ubuntu1.7",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-gnutls-bin-3.6.13-2ubuntu1.7",
      "released": "2022-08-01T07:15:00Z"
    },
    {
      "platform": "linux",
      "product": "gnutls28",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "3.7.3-2",
      "fix": "DEBIAN-CVE-2021-4209",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-4209",
      "released": "2022-08-24T16:15:09Z"
    },
    {
      "platform": "linux",
      "product": "gnutls28",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "3.7.3-2",
      "fix": "DEBIAN-CVE-2021-4209",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-4209",
      "released": "2022-08-24T16:15:09Z"
    },
    {
      "platform": "linux",
      "product": "gnutls28",
      "release": "Debian 14",
      "fixedVersion": "3.7.3-2",
      "fix": "DEBIAN-CVE-2021-4209",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-4209",
      "released": "2022-08-24T16:15:09Z"
    },
    {
      "platform": "linux",
      "product": "guile-gnutls",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "3.6.13-2ubuntu1.7",
      "fix": "guile-gnutls 3.6.13-2ubuntu1.7",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-guile-gnutls-3.6.13-2ubuntu1.7",
      "released": "2022-08-01T07:15:00Z"
    },
    {
      "platform": "linux",
      "product": "libgnutls-dane0",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "3.5.18-1ubuntu1.6",
      "fix": "libgnutls-dane0 3.5.18-1ubuntu1.6",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-libgnutls-dane0-3.5.18-1ubuntu1.6",
      "released": "2022-08-01T07:15:00Z"
    },
    {
      "platform": "linux",
      "product": "libgnutls-dane0",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "3.6.13-2ubuntu1.7",
      "fix": "libgnutls-dane0 3.6.13-2ubuntu1.7",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-libgnutls-dane0-3.6.13-2ubuntu1.7",
      "released": "2022-08-01T07:15:00Z"
    },
    {
      "platform": "linux",
      "product": "libgnutls-openssl27",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "3.5.18-1ubuntu1.6",
      "fix": "libgnutls-openssl27 3.5.18-1ubuntu1.6",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-libgnutls-openssl27-3.5.18-1ubuntu1.6",
      "released": "2022-08-01T07:15:00Z"
    },
    {
      "platform": "linux",
      "product": "libgnutls-openssl27",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "3.6.13-2ubuntu1.7",
      "fix": "libgnutls-openssl27 3.6.13-2ubuntu1.7",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-libgnutls-openssl27-3.6.13-2ubuntu1.7",
      "released": "2022-08-01T07:15:00Z"
    },
    {
      "platform": "linux",
      "product": "libgnutls30",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "3.5.18-1ubuntu1.6",
      "fix": "libgnutls30 3.5.18-1ubuntu1.6",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-libgnutls30-3.5.18-1ubuntu1.6",
      "released": "2022-08-01T07:15:00Z"
    },
    {
      "platform": "linux",
      "product": "libgnutls30",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "3.6.13-2ubuntu1.7",
      "fix": "libgnutls30 3.6.13-2ubuntu1.7",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-libgnutls30-3.6.13-2ubuntu1.7",
      "released": "2022-08-01T07:15:00Z"
    },
    {
      "platform": "linux",
      "product": "libgnutlsxx28",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "3.5.18-1ubuntu1.6",
      "fix": "libgnutlsxx28 3.5.18-1ubuntu1.6",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-libgnutlsxx28-3.5.18-1ubuntu1.6",
      "released": "2022-08-01T07:15:00Z"
    },
    {
      "platform": "linux",
      "product": "libgnutlsxx28",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "3.6.13-2ubuntu1.7",
      "fix": "libgnutlsxx28 3.6.13-2ubuntu1.7",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-libgnutlsxx28-3.6.13-2ubuntu1.7",
      "released": "2022-08-01T07:15:00Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T06:59:42Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}