{
  "cveId": "CVE-2021-20305",
  "url": "https://patchblox.com/security/cve/CVE-2021-20305",
  "summary": "CVE-2021-20305 is fixed in 14 products on 1 platform, first by libhogweed4 3.4-1ubuntu0.1, released April 5, 2021. It is not reported as exploited. Patch Radar priority: High.",
  "title": "libhogweed6t64: A flaw was found in Nettle in versions before 3.7.2, where several Nettlesignature verification functions (GOST DSA,...",
  "description": "A flaw was found in Nettle in versions before 3.7.2, where several Nettlesignature verification functions (GOST DSA, EDDSA \u0026 ECDSA) result in theElliptic Curve Cryptography point (ECC) multiply function being called without-of-range scalers, possibly resulting in incorrect results. This flawallows an attacker to force an invalid signature, causing an assertionfailure or possible validation. The highest threat to this vulnerability isto confidentiality, integrity, as well as system availability.",
  "published": "2021-04-05T15:15:00Z",
  "severity": "Medium",
  "cvss": 8.1,
  "epss": 0.01674,
  "epssPercentile": 0.76996,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "gnutls",
      "release": "RHEL 8",
      "fixedVersion": "0:3.6.14-8.el8_3",
      "fix": "RHSA-2021:1206",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2021-1206",
      "released": "2021-04-14T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "gnutls",
      "release": "ol 8",
      "fixedVersion": "0:3.6.14-8.el8_3",
      "fix": "ELSA-2021-1206",
      "url": "https://patchblox.com/security/fix/linux/elsa-2021-1206",
      "released": "2021-04-16T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "gnutls-c\u002B\u002B",
      "release": "RHEL 8",
      "fixedVersion": "0:3.6.14-8.el8_3",
      "fix": "RHSA-2021:1206",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2021-1206",
      "released": "2021-04-14T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "gnutls-c\u002B\u002B",
      "release": "ol 8",
      "fixedVersion": "0:3.6.14-8.el8_3",
      "fix": "ELSA-2021-1206",
      "url": "https://patchblox.com/security/fix/linux/elsa-2021-1206",
      "released": "2021-04-16T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "gnutls-dane",
      "release": "RHEL 8",
      "fixedVersion": "0:3.6.14-8.el8_3",
      "fix": "RHSA-2021:1206",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2021-1206",
      "released": "2021-04-14T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "gnutls-dane",
      "release": "ol 8",
      "fixedVersion": "0:3.6.14-8.el8_3",
      "fix": "ELSA-2021-1206",
      "url": "https://patchblox.com/security/fix/linux/elsa-2021-1206",
      "released": "2021-04-16T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "gnutls-devel",
      "release": "RHEL 8",
      "fixedVersion": "0:3.6.14-8.el8_3",
      "fix": "RHSA-2021:1206",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2021-1206",
      "released": "2021-04-14T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "gnutls-devel",
      "release": "ol 8",
      "fixedVersion": "0:3.6.14-8.el8_3",
      "fix": "ELSA-2021-1206",
      "url": "https://patchblox.com/security/fix/linux/elsa-2021-1206",
      "released": "2021-04-16T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "gnutls-utils",
      "release": "RHEL 8",
      "fixedVersion": "0:3.6.14-8.el8_3",
      "fix": "RHSA-2021:1206",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2021-1206",
      "released": "2021-04-14T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "gnutls-utils",
      "release": "ol 8",
      "fixedVersion": "0:3.6.14-8.el8_3",
      "fix": "ELSA-2021-1206",
      "url": "https://patchblox.com/security/fix/linux/elsa-2021-1206",
      "released": "2021-04-16T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libhogweed4",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "3.4-1ubuntu0.1",
      "fix": "libhogweed4 3.4-1ubuntu0.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-libhogweed4-3.4-1ubuntu0.1",
      "released": "2021-04-05T15:15:00Z"
    },
    {
      "platform": "linux",
      "product": "libhogweed5",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "3.5.1\u002Breally3.5.1-2ubuntu0.1",
      "fix": "libhogweed5 3.5.1\u002Breally3.5.1-2ubuntu0.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-libhogweed5-3.5.1-really3.5.1-2ubuntu0.1",
      "released": "2021-04-05T15:15:00Z"
    },
    {
      "platform": "linux",
      "product": "libhogweed6t64",
      "release": "Ubuntu 24.10 (oracular)",
      "fixedVersion": "3.7-2.1ubuntu1",
      "fix": "libhogweed6t64 3.7-2.1ubuntu1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-oracular-libhogweed6t64-3.7-2.1ubuntu1",
      "released": "2026-01-16T01:42:22Z"
    },
    {
      "platform": "linux",
      "product": "libhogweed6t64",
      "release": "Ubuntu 25.04 (plucky)",
      "fixedVersion": "3.7-2.1ubuntu1",
      "fix": "libhogweed6t64 3.7-2.1ubuntu1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-plucky-libhogweed6t64-3.7-2.1ubuntu1",
      "released": "2026-01-16T01:42:24Z"
    },
    {
      "platform": "linux",
      "product": "libnettle6",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "3.4-1ubuntu0.1",
      "fix": "libnettle6 3.4-1ubuntu0.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-libnettle6-3.4-1ubuntu0.1",
      "released": "2021-04-05T15:15:00Z"
    },
    {
      "platform": "linux",
      "product": "libnettle7",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "3.5.1\u002Breally3.5.1-2ubuntu0.1",
      "fix": "libnettle7 3.5.1\u002Breally3.5.1-2ubuntu0.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-libnettle7-3.5.1-really3.5.1-2ubuntu0.1",
      "released": "2021-04-05T15:15:00Z"
    },
    {
      "platform": "linux",
      "product": "libnettle8t64",
      "release": "Ubuntu 24.10 (oracular)",
      "fixedVersion": "3.7-2.1ubuntu1",
      "fix": "libnettle8t64 3.7-2.1ubuntu1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-oracular-libnettle8t64-3.7-2.1ubuntu1",
      "released": "2026-01-16T01:42:22Z"
    },
    {
      "platform": "linux",
      "product": "libnettle8t64",
      "release": "Ubuntu 25.04 (plucky)",
      "fixedVersion": "3.7-2.1ubuntu1",
      "fix": "libnettle8t64 3.7-2.1ubuntu1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-plucky-libnettle8t64-3.7-2.1ubuntu1",
      "released": "2026-01-16T01:42:24Z"
    },
    {
      "platform": "linux",
      "product": "nettle",
      "release": "RHEL 8",
      "fixedVersion": "0:3.4.1-4.el8_3",
      "fix": "RHSA-2021:1206",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2021-1206",
      "released": "2021-04-14T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "nettle",
      "release": "ol 8",
      "fixedVersion": "0:3.4.1-4.el8_3",
      "fix": "ELSA-2021-1206",
      "url": "https://patchblox.com/security/fix/linux/elsa-2021-1206",
      "released": "2021-04-16T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "nettle-bin",
      "release": "Ubuntu 18.04.6 LTS (bionic)",
      "fixedVersion": "3.4-1ubuntu0.1",
      "fix": "nettle-bin 3.4-1ubuntu0.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-bionic-nettle-bin-3.4-1ubuntu0.1",
      "released": "2021-04-05T15:15:00Z"
    },
    {
      "platform": "linux",
      "product": "nettle-bin",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "3.5.1\u002Breally3.5.1-2ubuntu0.1",
      "fix": "nettle-bin 3.5.1\u002Breally3.5.1-2ubuntu0.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-nettle-bin-3.5.1-really3.5.1-2ubuntu0.1",
      "released": "2021-04-05T15:15:00Z"
    },
    {
      "platform": "linux",
      "product": "nettle-bin",
      "release": "Ubuntu 24.10 (oracular)",
      "fixedVersion": "3.7-2.1ubuntu1",
      "fix": "nettle-bin 3.7-2.1ubuntu1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-oracular-nettle-bin-3.7-2.1ubuntu1",
      "released": "2026-01-16T01:42:22Z"
    },
    {
      "platform": "linux",
      "product": "nettle-bin",
      "release": "Ubuntu 25.04 (plucky)",
      "fixedVersion": "3.7-2.1ubuntu1",
      "fix": "nettle-bin 3.7-2.1ubuntu1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-plucky-nettle-bin-3.7-2.1ubuntu1",
      "released": "2026-01-16T01:42:24Z"
    },
    {
      "platform": "linux",
      "product": "nettle-devel",
      "release": "RHEL 8",
      "fixedVersion": "0:3.4.1-4.el8_3",
      "fix": "RHSA-2021:1206",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2021-1206",
      "released": "2021-04-14T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "nettle-devel",
      "release": "ol 8",
      "fixedVersion": "0:3.4.1-4.el8_3",
      "fix": "ELSA-2021-1206",
      "url": "https://patchblox.com/security/fix/linux/elsa-2021-1206",
      "released": "2021-04-16T00:00:00Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-09T07:25:28Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}