CVE-2021-34523🔥 Known Exploited (CISA KEV)CRITICAL9.0CVSS Severity ScoreEPSS Score38.0840%EPSS Percentile96.42thPublished2021-07-14Last Modified2025-10-30Data SourcesNVDCISA KEVFIRST.org EPSSVulnerability DescriptionMicrosoft Exchange Server Elevation of Privilege VulnerabilityAffected Platforms (CPE)📦MicrosoftExchange Server= 2013= 2016= 2019References & Advisories🔗 http://packetstormsecurity.com/files/163895/Microsoft-Exchange-ProxyShell-Remote-Code-Execution.html🔗 https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34523🔗 https://www.zerodayinitiative.com/advisories/ZDI-21-822/🔗 http://packetstormsecurity.com/files/163895/Microsoft-Exchange-ProxyShell-Remote-Code-Execution.html🔗 https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34523🔗 https://www.zerodayinitiative.com/advisories/ZDI-21-822/🔗 https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-34523