{"history":[{"alert":0,"cve":"CVE-2021-42321","id":22292,"kind":"epss","observed_at":1794500401,"payload":"{\"date\": \"2026-11-12\", \"epss\": 0.91737, \"percentile\": 0.99818}"},{"alert":0,"cve":"CVE-2021-42321","id":19911,"kind":"epss","observed_at":1794327601,"payload":"{\"date\": \"2026-11-10\", \"epss\": 0.91737, \"percentile\": 0.99817}"},{"alert":0,"cve":"CVE-2021-42321","id":17877,"kind":"epss","observed_at":1794241201,"payload":"{\"date\": \"2026-11-09\", \"epss\": 0.91737, \"percentile\": 0.99817}"},{"alert":0,"cve":"CVE-2021-42321","id":15941,"kind":"epss","observed_at":1794154800,"payload":"{\"date\": \"2026-11-08\", \"epss\": 0.91737, \"percentile\": 0.99816}"},{"alert":0,"cve":"CVE-2021-42321","id":13919,"kind":"epss","observed_at":1794068402,"payload":"{\"date\": \"2026-11-07\", \"epss\": 0.91737, \"percentile\": 0.99816}"},{"alert":0,"cve":"CVE-2021-42321","id":11701,"kind":"epss","observed_at":1793982001,"payload":"{\"date\": \"2026-11-06\", \"epss\": 0.91737, \"percentile\": 0.99816}"},{"alert":0,"cve":"CVE-2021-42321","id":9687,"kind":"epss","observed_at":1793938800,"payload":"{\"date\": \"2026-11-05\", \"epss\": 0.91737, \"percentile\": 0.99816}"},{"alert":1,"cve":"CVE-2021-42321","id":8371,"kind":"cna","observed_at":1793852400,"payload":"{\"containers\": {\"adp\": [{\"providerMetadata\": {\"dateUpdated\": \"2024-08-04T03:30:38.363Z\", \"orgId\": \"af854a3a-2127-422b-91ae-364da2661108\", \"shortName\": \"CVE\"}, \"references\": [{\"tags\": [\"x_refsource_MISC\", \"x_transferred\"], \"url\": \"https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-42321\"}, {\"tags\": [\"x_refsource_MISC\", \"x_transferred\"], \"url\": \"http://packetstormsecurity.com/files/166153/Microsoft-Exchange-Server-Remote-Code-Execution.html\"}, {\"tags\": [\"x_refsource_MISC\", \"x_transferred\"], \"url\": \"http://packetstormsecurity.com/files/168131/Microsoft-Exchange-Server-ChainedSerializationBinder-Remote-Code-Execution.html\"}], \"title\": \"CVE Program Container\"}, {\"metrics\": [{\"other\": {\"content\": {\"id\": \"CVE-2021-42321\", \"options\": [{\"Exploitation\": \"active\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"total\"}], \"role\": \"CISA Coordinator\", \"timestamp\": \"2024-01-03T16:43:32.753195Z\", \"version\": \"2.0.3\"}, \"type\": \"ssvc\"}}, {\"other\": {\"content\": {\"dateAdded\": \"2021-11-17\", \"reference\": \"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-42321\"}, \"type\": \"kev\"}}], \"problemTypes\": [{\"descriptions\": [{\"description\": \"CWE-noinfo Not enough information\", \"lang\": \"en\", \"type\": \"CWE\"}]}], \"providerMetadata\": {\"dateUpdated\": \"2025-10-21T23:25:25.274Z\", \"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\"}, \"references\": [{\"tags\": [\"government-resource\"], \"url\": \"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-42321\"}], \"timeline\": [{\"lang\": \"en\", \"time\": \"2021-11-17T00:00:00.000Z\", \"value\": \"CVE-2021-42321 added to CISA KEV\"}], \"title\": \"CISA ADP Vulnrichment\"}], \"cna\": {\"affected\": [{\"platforms\": [\"x64-based Systems\"], \"product\": \"Microsoft Exchange Server 2016 Cumulative Update 21\", \"vendor\": \"Microsoft\", \"versions\": [{\"lessThan\": \"15.01.2308.020\", \"status\": \"affected\", \"version\": \"15.01.0\", \"versionType\": \"custom\"}]}, {\"platforms\": [\"x64-based Systems\"], \"product\": \"Microsoft Exchange Server 2016 Cumulative Update 22\", \"vendor\": \"Microsoft\", \"versions\": [{\"lessThan\": \"15.01.2375.017\", \"status\": \"affected\", \"version\": \"15.0.0\", \"versionType\": \"custom\"}]}, {\"platforms\": [\"x64-based Systems\"], \"product\": \"Microsoft Exchange Server 2019 Cumulative Update 10\", \"vendor\": \"Microsoft\", \"versions\": [{\"lessThan\": \"15.02.0792.019\", \"status\": \"affected\", \"version\": \"15.02.0\", \"versionType\": \"custom\"}]}, {\"platforms\": [\"x64-based Systems\"], \"product\": \"Microsoft Exchange Server 2019 Cumulative Update 11\", \"vendor\": \"Microsoft\", \"versions\": [{\"lessThan\": \"15.02.0986.014\", \"status\": \"affected\", \"version\": \"15.02.0\", \"versionType\": \"custom\"}]}], \"cpeApplicability\": [{\"nodes\": [{\"cpeMatch\": [{\"criteria\": \"cpe:2.3:a:microsoft:exchange_server:*:cumulative_update_21:*:*:*:*:*:*\", \"versionEndExcluding\": \"15.01.2308.020\", \"versionStartIncluding\": \"15.01.0\", \"vulnerable\": true}, {\"criteria\": \"cpe:2.3:a:microsoft:exchange_server:*:cumulative_update_10:*:*:*:*:*:*\", \"versionEndExcluding\": \"15.02.0792.019\", \"versionStartIncluding\": \"15.02.0\", \"vulnerable\": true}, {\"criteria\": \"cpe:2.3:a:microsoft:exchange_server:*:cumulative_update_22:*:*:*:*:*:*\", \"versionEndExcluding\": \"15.01.2375.017\", \"versionStartIncluding\": \"15.0.0\", \"vulnerable\": true}, {\"criteria\": \"cpe:2.3:a:microsoft:exchange_server:*:cumulative_update_11:*:*:*:*:*:*\", \"versionEndExcluding\": \"15.02.0986.014\", \"versionStartIncluding\": \"15.02.0\", \"vulnerable\": true}], \"negate\": false, \"operator\": \"OR\"}]}], \"datePublic\": \"2021-11-09T08:00:00.000Z\", \"descriptions\": [{\"lang\": \"en-US\", \"value\": \"Microsoft Exchange Server Remote Code Execution Vulnerability\"}], \"metrics\": [{\"cvssV3_1\": {\"baseScore\": 8.8, \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C\", \"version\": \"3.1\"}, \"format\": \"CVSS\", \"scenarios\": [{\"lang\": \"en-US\", \"value\": \"GENERAL\"}]}], \"problemTypes\": [{\"descriptions\": [{\"description\": \"Remote Code Execution\", \"lang\": \"en-US\", \"type\": \"Impact\"}]}], \"providerMetadata\": {\"dateUpdated\": \"2026-08-19T16:27:07.165Z\", \"orgId\": \"f38d906d-7342-40ea-92c1-6c4a2c6478c8\", \"shortName\": \"microsoft\"}, \"references\": [{\"name\": \"Microsoft Exchange Server Remote Code Execution Vulnerability\", \"tags\": [\"vendor-advisory\", \"patch\"], \"url\": \"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-42321\"}], \"title\": \"Microsoft Exchange Server Remote Code Execution Vulnerability\"}}, \"cveMetadata\": {\"assignerOrgId\": \"f38d906d-7342-40ea-92c1-6c4a2c6478c8\", \"assignerShortName\": \"microsoft\", \"cveId\": \"CVE-2021-42321\", \"datePublished\": \"2021-11-10T00:47:43.000Z\", \"dateReserved\": \"2021-10-12T00:00:00.000Z\", \"dateUpdated\": \"2026-08-19T16:27:07.165Z\", \"state\": \"PUBLISHED\"}, \"dataType\": \"CVE_RECORD\", \"dataVersion\": \"5.2\"}"},{"alert":0,"cve":"CVE-2021-42321","id":7235,"kind":"epss","observed_at":1793809200,"payload":"{\"date\": \"2026-11-04\", \"epss\": 0.91737, \"percentile\": 0.99816}"},{"alert":0,"cve":"CVE-2021-42321","id":5012,"kind":"epss","observed_at":1793722800,"payload":"{\"date\": \"2026-11-03\", \"epss\": 0.91737, \"percentile\": 0.99815}"},{"alert":0,"cve":"CVE-2021-42321","id":2794,"kind":"epss","observed_at":1793665375,"payload":"{\"date\": \"2026-11-02\", \"epss\": 0.91737, \"percentile\": 0.99815}"},{"alert":1,"cve":"CVE-2021-42321","id":1478,"kind":"kev","observed_at":1793665375,"payload":"{\"cveID\": \"CVE-2021-42321\", \"cwes\": [\"CWE-184\", \"CWE-502\"], \"dateAdded\": \"2021-11-17\", \"dueDate\": \"2021-12-01\", \"forensicTriage\": \"No\", \"knownRansomwareCampaignUse\": \"Known\", \"notes\": \"https://nvd.nist.gov/vuln/detail/CVE-2021-42321\", \"product\": \"Exchange\", \"requiredAction\": \"Apply updates per vendor instructions.\", \"shortDescription\": \"An authenticated attacker could leverage improper validation in cmdlet arguments within Microsoft Exchange and perform remote code execution.\", \"vendorProject\": \"Microsoft\", \"vulnerabilityName\": \"Microsoft Exchange Server Remote Code Execution Vulnerability\"}"}],"record":{"affected":[{"platforms":["x64-based Systems"],"product":"Microsoft Exchange Server 2016 Cumulative Update 21","vendor":"Microsoft","versions":[{"lessThan":"15.01.2308.020","status":"affected","version":"15.01.0","versionType":"custom"}]},{"platforms":["x64-based Systems"],"product":"Microsoft Exchange Server 2016 Cumulative Update 22","vendor":"Microsoft","versions":[{"lessThan":"15.01.2375.017","status":"affected","version":"15.0.0","versionType":"custom"}]},{"platforms":["x64-based Systems"],"product":"Microsoft Exchange Server 2019 Cumulative Update 10","vendor":"Microsoft","versions":[{"lessThan":"15.02.0792.019","status":"affected","version":"15.02.0","versionType":"custom"}]},{"platforms":["x64-based Systems"],"product":"Microsoft Exchange Server 2019 Cumulative Update 11","vendor":"Microsoft","versions":[{"lessThan":"15.02.0986.014","status":"affected","version":"15.02.0","versionType":"custom"}]}],"cna":{"containers":{"adp":[{"providerMetadata":{"dateUpdated":"2024-08-04T03:30:38.363Z","orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE"},"references":[{"tags":["x_refsource_MISC","x_transferred"],"url":"https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-42321"},{"tags":["x_refsource_MISC","x_transferred"],"url":"http://packetstormsecurity.com/files/166153/Microsoft-Exchange-Server-Remote-Code-Execution.html"},{"tags":["x_refsource_MISC","x_transferred"],"url":"http://packetstormsecurity.com/files/168131/Microsoft-Exchange-Server-ChainedSerializationBinder-Remote-Code-Execution.html"}],"title":"CVE Program Container"},{"metrics":[{"other":{"content":{"id":"CVE-2021-42321","options":[{"Exploitation":"active"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","timestamp":"2024-01-03T16:43:32.753195Z","version":"2.0.3"},"type":"ssvc"}},{"other":{"content":{"dateAdded":"2021-11-17","reference":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-42321"},"type":"kev"}}],"problemTypes":[{"descriptions":[{"description":"CWE-noinfo Not enough information","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2025-10-21T23:25:25.274Z","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP"},"references":[{"tags":["government-resource"],"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-42321"}],"timeline":[{"lang":"en","time":"2021-11-17T00:00:00.000Z","value":"CVE-2021-42321 added to CISA KEV"}],"title":"CISA ADP Vulnrichment"}],"cna":{"affected":[{"platforms":["x64-based Systems"],"product":"Microsoft Exchange Server 2016 Cumulative Update 21","vendor":"Microsoft","versions":[{"lessThan":"15.01.2308.020","status":"affected","version":"15.01.0","versionType":"custom"}]},{"platforms":["x64-based Systems"],"product":"Microsoft Exchange Server 2016 Cumulative Update 22","vendor":"Microsoft","versions":[{"lessThan":"15.01.2375.017","status":"affected","version":"15.0.0","versionType":"custom"}]},{"platforms":["x64-based Systems"],"product":"Microsoft Exchange Server 2019 Cumulative Update 10","vendor":"Microsoft","versions":[{"lessThan":"15.02.0792.019","status":"affected","version":"15.02.0","versionType":"custom"}]},{"platforms":["x64-based Systems"],"product":"Microsoft Exchange Server 2019 Cumulative Update 11","vendor":"Microsoft","versions":[{"lessThan":"15.02.0986.014","status":"affected","version":"15.02.0","versionType":"custom"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:a:microsoft:exchange_server:*:cumulative_update_21:*:*:*:*:*:*","versionEndExcluding":"15.01.2308.020","versionStartIncluding":"15.01.0","vulnerable":true},{"criteria":"cpe:2.3:a:microsoft:exchange_server:*:cumulative_update_10:*:*:*:*:*:*","versionEndExcluding":"15.02.0792.019","versionStartIncluding":"15.02.0","vulnerable":true},{"criteria":"cpe:2.3:a:microsoft:exchange_server:*:cumulative_update_22:*:*:*:*:*:*","versionEndExcluding":"15.01.2375.017","versionStartIncluding":"15.0.0","vulnerable":true},{"criteria":"cpe:2.3:a:microsoft:exchange_server:*:cumulative_update_11:*:*:*:*:*:*","versionEndExcluding":"15.02.0986.014","versionStartIncluding":"15.02.0","vulnerable":true}],"negate":false,"operator":"OR"}]}],"datePublic":"2021-11-09T08:00:00.000Z","descriptions":[{"lang":"en-US","value":"Microsoft Exchange Server Remote Code Execution Vulnerability"}],"metrics":[{"cvssV3_1":{"baseScore":8.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C","version":"3.1"},"format":"CVSS","scenarios":[{"lang":"en-US","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"description":"Remote Code Execution","lang":"en-US","type":"Impact"}]}],"providerMetadata":{"dateUpdated":"2026-08-19T16:27:07.165Z","orgId":"f38d906d-7342-40ea-92c1-6c4a2c6478c8","shortName":"microsoft"},"references":[{"name":"Microsoft Exchange Server Remote Code Execution Vulnerability","tags":["vendor-advisory","patch"],"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-42321"}],"title":"Microsoft Exchange Server Remote Code Execution Vulnerability"}},"cveMetadata":{"assignerOrgId":"f38d906d-7342-40ea-92c1-6c4a2c6478c8","assignerShortName":"microsoft","cveId":"CVE-2021-42321","datePublished":"2021-11-10T00:47:43.000Z","dateReserved":"2021-10-12T00:00:00.000Z","dateUpdated":"2026-08-19T16:27:07.165Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"cna_checked":1794349204,"cve":"CVE-2021-42321","description":"Microsoft Exchange Server Remote Code Execution Vulnerability","epss":{"date":"2026-11-12","epss":0.91737,"percentile":0.99818},"epss_checked":1794522003,"first_seen":1793665375,"kev":{"cveID":"CVE-2021-42321","cwes":["CWE-184","CWE-502"],"dateAdded":"2021-11-17","dueDate":"2021-12-01","forensicTriage":"No","knownRansomwareCampaignUse":"Known","notes":"https://nvd.nist.gov/vuln/detail/CVE-2021-42321","product":"Exchange","requiredAction":"Apply updates per vendor instructions.","shortDescription":"An authenticated attacker could leverage improper validation in cmdlet arguments within Microsoft Exchange and perform remote code execution.","vendorProject":"Microsoft","vulnerabilityName":"Microsoft Exchange Server Remote Code Execution Vulnerability"},"kev_checked":1794522003,"products":"Microsoft Microsoft Exchange Server 2016 Cumulative Update 21, Microsoft Microsoft Exchange Server 2016 Cumulative Update 22, Microsoft Microsoft Exchange Server 2019 Cumulative Update 10, Microsoft Microsoft Exchange Server 2019 Cumulative Update 11","references":["https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-42321","https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-42321","http://packetstormsecurity.com/files/166153/Microsoft-Exchange-Server-Remote-Code-Execution.html","http://packetstormsecurity.com/files/168131/Microsoft-Exchange-Server-ChainedSerializationBinder-Remote-Code-Execution.html","https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-42321"],"score":{"baseScore":8.8,"baseSeverity":"HIGH","provider":"microsoft","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C","version":"3.1"},"solutions":"","state":"PUBLISHED","title":"Microsoft Exchange Server Remote Code Execution Vulnerability","updated_at":1794500401,"workarounds":""},"sources":[]}
