{"id":"CVE-2020-17144","kind":"vulnerability","aliases":["CVE-2020-17144"],"related":[],"title":"Microsoft Exchange Server: Microsoft Exchange Server Remote Code Execution Vulnerability","description":"Microsoft Exchange Server improperly validates cmdlet arguments which allow an attacker to perform remote code execution.\n\nCISA required action: Apply updates per vendor instructions.","summary":"Microsoft Exchange Server does not properly validate cmdlet arguments, letting an attacker run code remotely on the server. CISA lists it as actively exploited in the wild.","severity":"high","cvss":8.8,"epss":0.36514,"exploited":true,"exploited_at":"2021-11-03T00:00:00+00:00","products":[{"name":"Microsoft Exchange Server","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["exchange-server","exploited","infrastructure","self-hosted","windows"],"not_affected_if":["exchange-online","patched-server"],"how_to_check":null,"fix":"Apply the Microsoft updates for Exchange Server per vendor instructions, as CISA requires; the specific patched build numbers are not in the sources.","status":"open","published_at":"2020-12-10T00:15:16+00:00","first_seen_at":"2026-10-23T19:11:53+00:00","triaged_at":"2026-10-23T21:39:26+00:00","updated_at":"2026-10-23T21:57:35+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-10-23T21:39:26Z","model":"claude-haiku-5-5","output":{"fix":"Apply the Microsoft updates for Exchange Server per vendor instructions, as CISA requires; the specific patched build numbers are not in the sources.","reach":"network","impact":"high","summary":"Microsoft Exchange Server does not properly validate cmdlet arguments, letting an attacker run code remotely on the server. CISA lists it as actively exploited in the wild.","category":"infrastructure","who_cares":["exchange-server","windows","self-hosted"],"confidence":0.6,"needs_auth":"yes","worst_case":"Attacker runs arbitrary code on the Exchange server with high privileges.","analyst_note":"Find the affected and fixed Exchange build numbers and a detection method (e.g. Microsoft security update guide for CVE-2020-17144 and the CISA KEV entry).","how_to_check":"unknown","needs_analyst":true,"not_affected_if":["exchange-online","patched-server"],"user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000462,"input_tokens":2827,"output_tokens":359,"severity_before":"unknown"},"analyst_status":"queued","analyst_note":"Find the affected and fixed Exchange build numbers and a detection method (e.g. Microsoft security update guide for CVE-2020-17144 and the CISA KEV entry).","search":"'-17144':13A,16A '-2020':12A,15A 'action':74C 'activ':51B 'allow':64C 'appli':75C 'argument':37B,62C 'attack':40B,66C 'cisa':47B,72C 'cmdlet':36B,61C 'code':8A,42B,70C 'cve':11A,14A 'exchang':2A,5A,21B,30B,57C 'exchange':18A 'exchange-serv':20B 'execut':9A,71C 'exploit':23B,52B 'host':27B 'improp':59C 'infrastructur':24B 'instruct':79C 'let':38B 'list':48B 'microsoft':1A,4A,17A,29B,56C 'per':77C 'perform':68C 'proper':34B 'remot':7A,43B,69C 'requir':73C 'run':41B 'self':26B 'self-host':25B 'server':3A,6A,19A,22B,31B,46B,58C 'updat':76C 'valid':35B,60C 'vendor':78C 'vulner':10A 'wild':55B 'window':28B","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2020-12-10T00:15:16+00:00","kev":{"dateAdded":"2021-11-03","dueDate":"2022-05-03","requiredAction":"Apply updates per vendor instructions.","knownRansomwareCampaignUse":"Unknown"},"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:H","cvss_by":"secure@microsoft.com","poc_count":0,"sources":[{"source":"kev","external_id":"CVE-2020-17144","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2020-17144","severity":null,"published_at":"2021-11-03T00:00:00+00:00","modified_at":null,"first_seen_at":"2026-10-23T19:11:53+00:00","fetched_at":"2026-10-25T13:39:33+00:00","note":null},{"source":"epss","external_id":"CVE-2020-17144","url":"https://api.first.org/data/v1/epss?cve=CVE-2020-17144","severity":null,"published_at":null,"modified_at":null,"first_seen_at":"2026-10-23T19:13:44+00:00","fetched_at":"2026-10-23T19:13:44+00:00","note":null},{"source":"nvd","external_id":"CVE-2020-17144","url":"https://nvd.nist.gov/vuln/detail/CVE-2020-17144","severity":null,"published_at":"2020-12-10T00:15:16+00:00","modified_at":"2026-06-17T02:58:45+00:00","first_seen_at":"2026-10-23T21:57:35+00:00","fetched_at":"2026-10-23T21:57:35+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}