{
  "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-2021-1730",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2021-1730",
    "idYear": 2021,
    "status": "PUBLISHED",
    "publishedAt": "2021-02-25T23:01:30.000Z",
    "updatedAt": "2024-08-03T16:18:11.528Z",
    "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": "Microsoft Exchange Server Spoofing Vulnerability",
      "summary": "<p>A spoofing vulnerability exists in Microsoft Exchange Server which could result in an attack that would allow a malicious actor to impersonate the user.</p>\n<p>This update addresses this vulnerability.</p>\n<p>To prevent these types of attacks, Microsoft recommends customers to download inline images from different DNSdomains than the rest of OWA. Please see further instructions in the FAQ to put in place this mitigations.</p>",
      "affected": [
        {
          "vendor": "Microsoft",
          "product": "Microsoft Exchange Server 2019 Cumulative Update 7",
          "platforms": [
            "x64-based Systems"
          ],
          "versions": [
            {
              "version": "15.02.0",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "publication"
            }
          ]
        },
        {
          "vendor": "Microsoft",
          "product": "Microsoft Exchange Server 2016 Cumulative Update 18",
          "platforms": [
            "x64-based Systems"
          ],
          "versions": [
            {
              "version": "15.01.0",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "publication"
            }
          ]
        }
      ]
    }
  }
}