{"id":"CVE-2021-31207","aliases":[],"url":"https://o3.security/vulnerability/CVE-2021-31207","summary":"Microsoft Exchange Server Security Feature Bypass Vulnerability","details":"Microsoft Exchange Server Security Feature Bypass Vulnerability","published":"2021-05-11T19:15:10.397","modified":"2026-06-17T03:51:27.123","cvss":{"score":6.6,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H"},"epss":{"score":0.99782,"percentile":0.99956,"asOf":"2026-09-05"},"cisaKev":null,"exploitsKnown":4,"affectedPackages":[],"fix":null,"references":[{"type":"EXPLOIT","url":"http://packetstormsecurity.com/files/163895/Microsoft-Exchange-ProxyShell-Remote-Code-Execution.html"},{"type":"FIX","url":"https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31207"},{"type":"ADVISORY","url":"https://www.zerodayinitiative.com/advisories/ZDI-21-819/"},{"type":"EXPLOIT","url":"http://packetstormsecurity.com/files/163895/Microsoft-Exchange-ProxyShell-Remote-Code-Execution.html"},{"type":"FIX","url":"https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31207"},{"type":"ADVISORY","url":"https://www.zerodayinitiative.com/advisories/ZDI-21-819/"},{"type":"WEB","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-31207"}],"provenance":{"sources":["OSV.dev","NVD","FIRST.org (EPSS)"],"lastVerified":"2026-06-17T03:51:27.123"}}