{
  "schemaVersion": 1,
  "attribution": [
    {
      "source": "CISA Known Exploited Vulnerabilities",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "licence": "US government work"
    },
    {
      "source": "GitHub Advisory Database",
      "url": "https://github.com/advisories",
      "licence": "CC BY 4.0"
    },
    {
      "source": "Have I Been Pwned",
      "url": "https://haveibeenpwned.com/",
      "licence": "CC BY 4.0"
    },
    {
      "source": "CVE Program (CVE records)",
      "url": "https://www.cve.org/Legal/TermsOfUse",
      "licence": "CVE Terms of Use",
      "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.",
      "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss/",
      "licence": "free to use; FIRST requests attribution"
    }
  ],
  "record": {
    "id": "CVE-2021-0221",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2021-0221",
    "idYear": 2021,
    "status": "PUBLISHED",
    "publishedAt": "2021-01-15T17:36:01.999Z",
    "updatedAt": "2024-09-16T18:08:09.691Z",
    "importedAt": "2026-10-24T01:56:21.187Z",
    "snapshot": {
      "id": "cve_2026-10-24_midnight_baseline",
      "at": "2026-10-24T00:00:00.000Z",
      "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z"
    },
    "facts": {
      "title": "Junos OS: QFX Series: Traffic loop Denial of Service (DoS) upon receipt of specific IP multicast traffic",
      "summary": "In an EVPN/VXLAN scenario, if an IRB interface with a virtual gateway address (VGA) is configured on a PE, a traffic loop may occur upon receipt of specific IP multicast traffic. The traffic loop will cause interface traffic to increase abnormally, ultimately leading to a Denial of Service (DoS) in packet processing. The following command could be used to monitor the interface traffic: user@junos> monitor interface traffic Interface Link Input packets (pps) Output packets (pps) et-0/0/1 Up 6492089274364 (70994959) 6492089235319 (70994956) et-0/0/25 Up 343458103 (1) 156844 (0) ae0 Up 9132519197257 (70994959) 9132519139454 (70994956) This issue affects Juniper Networks Junos OS on QFX Series: all versions prior to 17.3R3-S10; 17.4 versions prior to 17.4R2-S12, 17.4R3-S3; 18.1 versions prior to 18.1R3-S11; 18.2 versions prior to 18.2R3-S6; 18.3 versions prior to 18.3R3-S4; 18.4 versions prior to 18.4R2-S5, 18.4R3-S5; 19.1 versions prior to 19.1R1-S6, 19.1R2-S2, 19.1R3-S3; 19.2 versions prior to 19.2R1-S5, 19.2R3-S1; 19.3 versions prior to 19.3R2-S5, 19.3R3; 19.4 versions prior to 19.4R2-S2, 19.4R3; 20.1 versions prior to 20.1R2; 20.2 versions prior to 20.2R1-S2, 20.2R2.",
      "affected": [
        {
          "vendor": "Juniper Networks",
          "product": "Junos OS",
          "platforms": [
            "QFX Series"
          ],
          "versions": [
            {
              "version": "unspecified",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "17.3R3-S10"
            },
            {
              "version": "17.4",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "17.4R2-S12, 17.4R3-S3"
            },
            {
              "version": "18.1",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "18.1R3-S11"
            },
            {
              "version": "18.2",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "18.2R3-S6"
            },
            {
              "version": "18.3",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "18.3R3-S4"
            },
            {
              "version": "18.4",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "18.4R2-S5, 18.4R3-S5"
            },
            {
              "version": "19.1",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "19.1R1-S6, 19.1R2-S2, 19.1R3-S3"
            },
            {
              "version": "19.2",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "19.2R1-S5, 19.2R3-S1"
            },
            {
              "version": "19.3",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "19.3R2-S5, 19.3R3"
            },
            {
              "version": "19.4",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "19.4R2-S2, 19.4R3"
            },
            {
              "version": "20.1",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "20.1R2"
            },
            {
              "version": "20.2",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "20.2R1-S2, 20.2R2"
            }
          ]
        }
      ]
    }
  }
}