ubuntu-cve-2023-26249
Vulnerability from osv_ubuntu
Published
2023-02-21 02:15
Modified
2026-04-22 07:45
Summary
Details

Knot Resolver before 5.6.0 enables attackers to consume its resources, launching amplification attacks and potentially causing a denial of service. Specifically, a single client query may lead to a hundred TCP connection attempts if a DNS server closes connections without providing a response.

Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
N/A (UNKNOWN)
medium
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "knot-resolver",
            "binary_version": "1.0.0~beta3-1ubuntu0.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "knot-resolver",
        "purl": "pkg:deb/ubuntu/knot-resolver@1.0.0~beta3-1ubuntu0.1~esm1?arch=source\u0026distro=esm-apps/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.0.0~beta2-123-g6134920-1",
        "1.0.0~beta3-1",
        "1.0.0~beta3-1ubuntu0.1~esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "knot-resolver",
            "binary_version": "2.1.1-1ubuntu0.1~esm2"
          },
          {
            "binary_name": "knot-resolver-module-http",
            "binary_version": "2.1.1-1ubuntu0.1~esm2"
          },
          {
            "binary_name": "libkres6",
            "binary_version": "2.1.1-1ubuntu0.1~esm2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:18.04:LTS",
        "name": "knot-resolver",
        "purl": "pkg:deb/ubuntu/knot-resolver@2.1.1-1ubuntu0.1~esm2?arch=source\u0026distro=esm-apps/bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.3.3-1",
        "1.5.0-4",
        "1.5.1-1",
        "1.5.2-1",
        "2.0.0-3",
        "2.1.0-1",
        "2.1.0-2",
        "2.1.1-1",
        "2.1.1-1ubuntu0.1~esm2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "knot-resolver",
            "binary_version": "3.2.1-3ubuntu2.2"
          },
          {
            "binary_name": "knot-resolver-module-http",
            "binary_version": "3.2.1-3ubuntu2.2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "knot-resolver",
        "purl": "pkg:deb/ubuntu/knot-resolver@3.2.1-3ubuntu2.2?arch=source\u0026distro=focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.2.1-3",
        "3.2.1-3ubuntu1",
        "3.2.1-3ubuntu2",
        "3.2.1-3ubuntu2.1",
        "3.2.1-3ubuntu2.2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "knot-resolver",
            "binary_version": "5.4.4-1ubuntu0.1~esm1"
          },
          {
            "binary_name": "knot-resolver-module-http",
            "binary_version": "5.4.4-1ubuntu0.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:22.04:LTS",
        "name": "knot-resolver",
        "purl": "pkg:deb/ubuntu/knot-resolver@5.4.4-1ubuntu0.1~esm1?arch=source\u0026distro=esm-apps/jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "5.3.1-1",
        "5.4.2-1",
        "5.4.3-1",
        "5.4.4-1",
        "5.4.4-1ubuntu0.1~esm1"
      ]
    }
  ],
  "aliases": [],
  "details": "Knot Resolver before 5.6.0 enables attackers to consume its resources, launching amplification attacks and potentially causing a denial of service. Specifically, a single client query may lead to a hundred TCP connection attempts if a DNS server closes connections without providing a response.",
  "id": "UBUNTU-CVE-2023-26249",
  "modified": "2026-04-22T07:45:16Z",
  "published": "2023-02-21T02:15:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2023-26249"
    },
    {
      "type": "REPORT",
      "url": "https://www.knot-resolver.cz/2023-01-26-knot-resolver-5.6.0.html"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2023-26249"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2023-26249"
  ]
}



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Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.