CVE-2021-26855EUVD-2021-1363903.03.2021, 00:15Microsoft Exchange Server Remote Code Execution VulnerabilitySSRFEnginsightProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVectorNISTPrimary9.1 CRITICALNETWORKLOWNONECVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:NmicrosoftCNA9.1 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N/E:F/RL:O/RC:CAwaiting analysisThis vulnerability is currently awaiting analysis.Base ScoreCVSS 3.xEPSS ScorePercentile: 99%Known Exploits!http://packetstormsecurity.com/files/161846/Microsoft-Exchange-2019-SSRF-Arbitrary-File-Write.htmlhttp://packetstormsecurity.com/files/161938/Microsoft-Exchange-ProxyLogon-Remote-Code-Execution.htmlhttp://packetstormsecurity.com/files/162610/Microsoft-Exchange-2019-Unauthenticated-Email-Download.htmlhttp://packetstormsecurity.com/files/162736/Microsoft-Exchange-ProxyLogon-Collector.htmlhttp://packetstormsecurity.com/files/161846/Microsoft-Exchange-2019-SSRF-Arbitrary-File-Write.htmlhttp://packetstormsecurity.com/files/161938/Microsoft-Exchange-ProxyLogon-Remote-Code-Execution.htmlhttp://packetstormsecurity.com/files/162610/Microsoft-Exchange-2019-Unauthenticated-Email-Download.htmlhttp://packetstormsecurity.com/files/162736/Microsoft-Exchange-ProxyLogon-Collector.htmlCommon Weakness EnumerationCWE-918 - Server-Side Request Forgery (SSRF)The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.Referenceshttp://packetstormsecurity.com/files/161846/Microsoft-Exchange-2019-SSRF-Arbitrary-File-Write.htmlhttp://packetstormsecurity.com/files/161938/Microsoft-Exchange-ProxyLogon-Remote-Code-Execution.htmlhttp://packetstormsecurity.com/files/162610/Microsoft-Exchange-2019-Unauthenticated-Email-Download.htmlhttp://packetstormsecurity.com/files/162736/Microsoft-Exchange-ProxyLogon-Collector.htmlhttps://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26855http://packetstormsecurity.com/files/161846/Microsoft-Exchange-2019-SSRF-Arbitrary-File-Write.htmlhttp://packetstormsecurity.com/files/161938/Microsoft-Exchange-ProxyLogon-Remote-Code-Execution.htmlhttp://packetstormsecurity.com/files/162610/Microsoft-Exchange-2019-Unauthenticated-Email-Download.htmlhttp://packetstormsecurity.com/files/162736/Microsoft-Exchange-ProxyLogon-Collector.htmlhttps://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26855https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26855