{"id":"CVE-2021-1730","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-1730","generatedAt":"2026-10-28T01:51:46.928Z","title":"<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> <p>This update addresses this vulnerability.</p> <p>To prevent these types of attacks,…","description":"<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>","published":"2021-02-25T23:15:14.000Z","lastModified":"2026-06-17T03:32:27.000Z","status":"Modified","sourceIdentifier":"secure@microsoft.com","cvss":{"version":"3.1","score":5.4,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N"},"cwe":[],"affected":["microsoft/exchange server"],"epss":{"score":0.01817,"percentile":0.7856,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (1.82%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-1730","tags":["Patch","Vendor Advisory"],"source":"secure@microsoft.com"},{"url":"https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-1730","tags":["Patch","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-1730","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}