{"id":"CVE-2021-22017","kind":"vulnerability","aliases":["CVE-2021-22017"],"related":[],"title":"VMware vCenter Server: VMware vCenter Server Improper Access Control","description":"Rhttproxy as used in vCenter Server contains a vulnerability due to improper implementation of URI normalization. A malicious actor with network access to port 443 on vCenter Server may exploit this issue to bypass proxy leading to internal endpoints being accessed.","summary":"VMware vCenter Server's rhttproxy component mishandles URI normalization, which lets a remote request reach endpoints it should not. CISA lists it as actively exploited, so attackers can reach vCenter management functions without the access they should need.","severity":"high","cvss":5.3,"epss":0.49177,"exploited":true,"exploited_at":"2022-01-10T00:00:00+00:00","products":[{"name":"VMware vCenter Server","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["exploited","infrastructure","self-hosted","vcenter","vmware"],"not_affected_if":["default-config"],"how_to_check":"Check the installed vCenter version in the VAMI web interface or with 'vpxd -v' on the appliance and compare it to the patched release in the VMware advisory.","fix":"Apply the VMware vCenter update that addresses CVE-2021-22017, per vendor instructions as CISA requires.","status":"open","published_at":"2021-09-23T13:15:08+00:00","first_seen_at":"2026-10-23T19:11:53+00:00","triaged_at":"2026-10-23T21:31:42+00:00","updated_at":"2026-10-23T21:57:35+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-10-23T21:31:42Z","model":"claude-haiku-5-5","output":{"fix":"Apply the VMware vCenter update that addresses CVE-2021-22017, per vendor instructions as CISA requires.\nunknown","reach":"network","impact":"high","summary":"VMware vCenter Server's rhttproxy component mishandles URI normalization, which lets a remote request reach endpoints it should not. CISA lists it as actively exploited, so attackers can reach vCenter management functions without the access they should need.","category":"infrastructure","who_cares":["vcenter","vmware","self-hosted"],"confidence":0.6,"needs_auth":"unknown","worst_case":"Attacker reaches vCenter internals without authorization, possibly taking control of management","analyst_note":"Pull the VMware advisory for CVE-2021-22017 to confirm affected and fixed vCenter versions and the exact attack preconditions.","how_to_check":"Check the installed vCenter version in the VAMI web interface or with 'vpxd -v' on the appliance and compare it to the patched release in the VMware advisory.\nunknown","needs_analyst":true,"not_affected_if":["default-config"],"user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000488,"input_tokens":2812,"output_tokens":414,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2021':11A,14A '-22017':12A,15A '443':88C 'access':8A,60B,85C,104C 'activ':49B 'actor':82C 'attack':52B 'bypass':97C 'cisa':45B 'compon':31B 'contain':70C 'control':9A 'cve':10A,13A 'due':73C 'endpoint':41B,102C 'exploit':19B,50B,93C 'function':57B 'host':23B 'implement':76C 'improp':7A,75C 'infrastructur':20B 'intern':101C 'issu':95C 'lead':99C 'let':36B 'list':46B 'malici':81C 'manag':56B 'may':92C 'mishandl':32B 'need':63B 'network':84C 'normal':34B,79C 'port':87C 'proxi':98C 'reach':40B,54B 'remot':38B 'request':39B 'rhttproxi':30B,64C 'self':22B 'self-host':21B 'server':3A,6A,18A,28B,69C,91C 'uri':33B,78C 'use':66C 'vcenter':2A,5A,17A,24B,27B,55B,68C,90C 'vmware':1A,4A,16A,25B,26B 'vulner':72C 'without':58B","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2021-09-23T13:15:08+00:00","kev":{"dateAdded":"2022-01-10","dueDate":"2022-01-24","requiredAction":"Apply updates per vendor instructions.","knownRansomwareCampaignUse":"Unknown"},"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","cvss_by":"nvd@nist.gov","poc_count":0,"sources":[{"source":"kev","external_id":"CVE-2021-22017","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2021-22017","severity":null,"published_at":"2022-01-10T00:00:00+00:00","modified_at":null,"first_seen_at":"2026-10-23T19:11:53+00:00","fetched_at":"2026-10-25T10:39:07+00:00","note":null},{"source":"epss","external_id":"CVE-2021-22017","url":"https://api.first.org/data/v1/epss?cve=CVE-2021-22017","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-2021-22017","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-22017","severity":null,"published_at":"2021-09-23T13:15:08+00:00","modified_at":"2026-06-17T03:36:33+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"}