{
  "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-2021-28816",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2021-28816",
    "idYear": 2021,
    "status": "PUBLISHED",
    "publishedAt": "2021-09-10T04:00:21.577Z",
    "updatedAt": "2024-09-17T01:56:02.590Z",
    "importedAt": "2026-10-24T01:56:26.894Z",
    "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": "Stack Buffer Overflow Vulnerabilities in QTS, QuTS hero, and QuTScloud",
      "summary": "A stack buffer overflow vulnerability has been reported to affect QNAP device running QTS, QuTScloud, QuTS hero. If exploited, this vulnerability allows attackers to execute arbitrary code. We have already fixed this vulnerability in the following versions of QTS, QuTScloud, QuTS hero: QTS 4.5.4.1715 build 20210630 and later QTS 5.0.0.1716 build 20210701 and later QTS 4.3.3.1693 build 20210624 and later QTS 4.3.6.1750 build 20210730 and later QuTScloud c4.5.6.1755 and later QuTS hero h4.5.4.1771 build 20210825 and later",
      "affected": [
        {
          "vendor": "QNAP Systems Inc.",
          "product": "QTS",
          "versions": [
            {
              "version": "unspecified",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "4.5.4.1715 build 20210630"
            },
            {
              "version": "unspecified",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "5.0.0.1716 build 20210701"
            },
            {
              "version": "unspecified",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "4.3.3.1693 build 20210624"
            },
            {
              "version": "unspecified",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "4.3.6.1750 build 20210730"
            }
          ]
        },
        {
          "vendor": "QNAP Systems Inc.",
          "product": "QuTScloud",
          "versions": [
            {
              "version": "unspecified",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "c4.5.6.1755"
            }
          ]
        },
        {
          "vendor": "QNAP Systems Inc.",
          "product": "QuTS hero",
          "versions": [
            {
              "version": "unspecified",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "h4.5.4.1771 build 20210825"
            }
          ]
        }
      ]
    }
  }
}