USN-5034-2 (UBUNTU-CVE-2021-3672)

Vulnerability from osv_ubuntu – Published: 2021-08-10 17:15 – Updated: 2026-06-25 10:46 – Source website
VLAI
Summary
c-ares vulnerability
Details

USN-5034-1 fixed a vulnerability in c-ares. This update provides the corresponding update for Ubuntu 16.04 ESM.

Original advisory details:

Philipp Jeitner and Haya Shulman discovered that c-ares incorrectly validated certain hostnames returned by DNS servers. A remote attacker could possibly use this issue to perform Domain Hijacking attacks.

References
To clipboard 

{
  "affected": [
    {
      "database_specific": {
        "cves_map": {
          "cves": [
            {
              "id": "CVE-2021-3672",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            }
          ],
          "ecosystem": "Ubuntu:Pro:16.04:LTS"
        }
      },
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "libc-ares2",
            "binary_version": "1.10.0-3ubuntu0.2+esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "c-ares",
        "purl": "pkg:deb/ubuntu/c-ares@1.10.0-3ubuntu0.2+esm1?arch=source\u0026distro=esm-infra/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.10.0-3ubuntu0.2+esm1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.10.0-2",
        "1.10.0-3",
        "1.10.0-3ubuntu0.1",
        "1.10.0-3ubuntu0.2"
      ]
    }
  ],
  "aliases": [],
  "details": "USN-5034-1 fixed a vulnerability in c-ares. This update provides\nthe corresponding update for Ubuntu 16.04 ESM.\n\nOriginal advisory details:\n\n Philipp Jeitner and Haya Shulman discovered that c-ares incorrectly\n validated certain hostnames returned by DNS servers. A remote attacker\n could possibly use this issue to perform Domain Hijacking attacks.\n",
  "id": "USN-5034-2",
  "modified": "2026-06-25T10:46:01Z",
  "published": "2021-08-10T17:15:47Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-5034-2"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2021-3672"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "summary": "c-ares vulnerability",
  "upstream": [
    "UBUNTU-CVE-2021-3672"
  ]
}



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