{
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      "text": "Medium"
    },
    "category": "csaf_vex",
    "csaf_version": "2.0",
    "distribution": {
      "text": "TuxCare License Agreement",
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        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
      }
    },
    "lang": "en",
    "notes": [
      {
        "category": "legal_disclaimer",
        "text": "This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Cloud Linux Inc. and provide a link to the original.",
        "title": "Terms of Use"
      }
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      "contact_details": "https://tuxcare.com/contact/",
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        "date": "2026-10-23T17:39:44Z",
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      "id": "CVE-2021-3672-ELS_OS-CLOUDLINUX7ELS",
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          "date": "2021-11-23T19:15:00Z",
          "number": "1",
          "summary": "Initial version"
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        {
          "date": "2026-10-23T17:39:44Z",
          "number": "2",
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      "status": "final",
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    },
    "title": "Security update on CVE-2021-3672"
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  "vulnerabilities": [
    {
      "cve": "CVE-2021-3672",
      "notes": [
        {
          "category": "description",
          "text": "A flaw was found in c-ares library, where a missing input validation check of host names returned by DNS (Domain Name Servers) can lead to output of wrong hostnames which might potentially lead to Domain Hijacking. The highest threat from this vulnerability is to confidentiality and integrity as well as system availability.",
          "title": "Vulnerability description"
        },
        {
          "category": "general",
          "text": "The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.",
          "title": "CVSS score applicability"
        }
      ],
      "product_status": {
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          "CloudLinux-7:c-ares-0:1.10.0-3.el7_9.1.tuxcare.els2.i686",
          "CloudLinux-7:c-ares-0:1.10.0-3.el7_9.1.tuxcare.els2.x86_64",
          "CloudLinux-7:c-ares-0:1.10.0-3.el7_9.1.x86_64",
          "CloudLinux-7:c-ares-devel-0:1.10.0-3.el7_9.1.i686",
          "CloudLinux-7:c-ares-devel-0:1.10.0-3.el7_9.1.tuxcare.els2.i686",
          "CloudLinux-7:c-ares-devel-0:1.10.0-3.el7_9.1.tuxcare.els2.x86_64",
          "CloudLinux-7:c-ares-devel-0:1.10.0-3.el7_9.1.x86_64"
        ]
      },
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        {
          "category": "self",
          "summary": "Canonical URL",
          "url": "https://cve.tuxcare.com/els/cve/CVE-2021-3672"
        },
        {
          "category": "external",
          "summary": "https://bugzilla.redhat.com/show_bug.cgi?id=1988342",
          "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1988342"
        },
        {
          "category": "external",
          "summary": "https://c-ares.haxx.se/adv_20210810.html",
          "url": "https://c-ares.haxx.se/adv_20210810.html"
        },
        {
          "category": "external",
          "summary": "https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf",
          "url": "https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf"
        },
        {
          "category": "external",
          "summary": "https://security.gentoo.org/glsa/202401-02",
          "url": "https://security.gentoo.org/glsa/202401-02"
        },
        {
          "category": "external",
          "summary": "https://www.oracle.com/security-alerts/cpujul2022.html",
          "url": "https://www.oracle.com/security-alerts/cpujul2022.html"
        }
      ],
      "release_date": "2021-11-23T19:15:00Z",
      "remediations": [
        {
          "category": "no_fix_planned",
          "date": "2026-10-15T12:47:38.705489Z",
          "details": "CVE-2021-3672 is a parsing flaw in c-ares that can cause an incorrect hostname to be returned from specially crafted DNS replies; it does not provide code execution or direct privilege escalation. Exploitation requires an attacker to control or successfully spoof DNS responses (high complexity) and is only meaningful if an application bases trust or caching decisions on the returned canonical name. In centrally managed server/VM environments that use designated recursive resolvers and do not implement application-level DNS caches, the practical risk is minimal, so this issue can be safely deprioritized.",
          "product_ids": [
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            "CloudLinux-7:c-ares-0:1.10.0-3.el7_9.1.tuxcare.els2.i686",
            "CloudLinux-7:c-ares-0:1.10.0-3.el7_9.1.tuxcare.els2.x86_64",
            "CloudLinux-7:c-ares-0:1.10.0-3.el7_9.1.x86_64",
            "CloudLinux-7:c-ares-devel-0:1.10.0-3.el7_9.1.i686",
            "CloudLinux-7:c-ares-devel-0:1.10.0-3.el7_9.1.tuxcare.els2.i686",
            "CloudLinux-7:c-ares-devel-0:1.10.0-3.el7_9.1.tuxcare.els2.x86_64",
            "CloudLinux-7:c-ares-devel-0:1.10.0-3.el7_9.1.x86_64"
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        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
            "baseScore": 5.6,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L",
            "version": "3.1"
          },
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            "CloudLinux-7:c-ares-devel-0:1.10.0-3.el7_9.1.i686",
            "CloudLinux-7:c-ares-devel-0:1.10.0-3.el7_9.1.tuxcare.els2.i686",
            "CloudLinux-7:c-ares-devel-0:1.10.0-3.el7_9.1.tuxcare.els2.x86_64",
            "CloudLinux-7:c-ares-devel-0:1.10.0-3.el7_9.1.x86_64"
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        }
      ],
      "threats": [
        {
          "category": "impact",
          "details": "Moderate"
        }
      ]
    }
  ]
}