{"id":"CVE-2021-36742","kind":"vulnerability","aliases":["CVE-2021-36742"],"related":[],"title":"Trend Micro Apex One, Apex One as a Service, and Worry-Free Business Security: Trend Micro Multiple Products Improper Input Validation Vulnerability","description":"A improper input validation vulnerability in Trend Micro Apex One, Apex One as a Service, OfficeScan XG and Worry-Free Business Security 10.0 SP1 allows a local attacker to escalate privileges on affected installations. Please note: an attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability.","summary":"Trend Micro Apex One, Apex One as a Service, OfficeScan XG and Worry-Free Business Security 10.0 SP1 have an improper input validation flaw. A local attacker who already runs low-privileged code on the machine can escalate to higher privileges.","severity":"high","cvss":7.8,"epss":0.01482,"exploited":true,"exploited_at":"2021-11-03T00:00:00+00:00","products":[{"name":"Trend Micro Apex One, Apex One as a Service, and Worry-Free Business Security","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["apex-one","exploited","self-hosted","trend-micro","vendor","windows","worry-free-business-security"],"not_affected_if":["managed-hosting","no-local-low-privilege-access"],"how_to_check":null,"fix":null,"status":"open","published_at":"2021-07-29T20:15:07+00:00","first_seen_at":"2026-10-23T19:11:53+00:00","triaged_at":"2026-10-23T20:29:39+00:00","updated_at":"2026-10-23T20:29:39+00:00","category":"vendor","confidence":0.7,"triage":{"at":"2026-10-23T20:29:39Z","model":"claude-haiku-5-5","output":{"fix":"unknown","summary":"Trend Micro Apex One, Apex One as a Service, OfficeScan XG and Worry-Free Business Security 10.0 SP1 have an improper input validation flaw. A local attacker who already runs low-privileged code on the machine can escalate to higher privileges.","category":"vendor","who_cares":["trend-micro","apex-one","worry-free-business-security","windows","self-hosted"],"confidence":0.7,"analyst_note":"CISA KEV lists this as exploited; find the vendor patch and affected build numbers from the Trend Micro advisory and NVD (https://nvd.nist.gov/vuln/detail/CVE-2021-36742).","how_to_check":"unknown","needs_analyst":true,"not_affected_if":["managed-hosting","no-local-low-privilege-access"],"severity_if_unknown":"high"},"cost_usd":0.000371,"input_tokens":2197,"output_tokens":303,"severity_before":"high"},"analyst_status":null,"analyst_note":null,"search":"'-2021':25A,28A '-36742':26A,29A '10.0':79B,128C 'a':37A 'abil':148C 'affect':138C 'allow':130C 'alreadi':91B 'and':39A 'apex':3A,5A,32A,34A,46B,64B,66B,113C,115C 'apex-on':45B 'as':36A 'attack':89B,133C,143C 'busi':14A,60B,77B,126C 'business':43A 'code':96B,154C 'cve':24A,27A 'escal':101B,135C 'execut':150C 'exploit':48B,162C 'first':145C 'flaw':86B 'free':13A,42A,59B,76B,125C 'higher':103B 'host':51B 'improp':20A,83B,106C 'input':21A,84B,107C 'instal':139C 'local':88B,132C 'low':94B,152C 'low-privileg':93B,151C 'machin':99B 'micro':2A,17A,31A,54B,63B,112C 'multipl':18A 'must':144C 'note':141C 'obtain':146C 'officescan':71B,120C 'one':4A,6A,33A,35A,47B,65B,67B,114C,116C 'order':160C 'pleas':140C 'privileg':95B,104B,136C,153C 'product':19A 'run':92B 'secur':15A,61B,78B,127C 'security':44A 'self':50B 'self-host':49B 'servic':9A,70B,119C 'service':38A 'sp1':80B,129C 'system':158C 'target':157C 'trend':1A,16A,30A,53B,62B,111C 'trend-micro':52B 'valid':22A,85B,108C 'vendor':55B 'vulner':23A,109C,164C 'window':56B 'worri':12A,58B,75B,124C 'worry':41A 'worry-fre':11A,74B,123C 'worry-free':40A 'worry-free-business-secur':57B 'xg':72B,121C","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2021-07-29T20:15:07+00:00","kev":{"dateAdded":"2021-11-03","dueDate":"2021-11-17","requiredAction":"Apply updates per vendor instructions.","knownRansomwareCampaignUse":"Unknown"},"cvss_vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvss_by":"nvd@nist.gov","poc_count":0,"sources":[{"source":"kev","external_id":"CVE-2021-36742","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2021-36742","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":"2026-10-25T11:39:18+00:00","note":null},{"source":"epss","external_id":"CVE-2021-36742","url":"https://api.first.org/data/v1/epss?cve=CVE-2021-36742","severity":null,"published_at":null,"modified_at":null,"first_seen_at":"2026-10-23T19:13:43+00:00","fetched_at":"2026-10-23T19:13:43+00:00","note":null},{"source":"nvd","external_id":"CVE-2021-36742","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-36742","severity":null,"published_at":"2021-07-29T20:15:07+00:00","modified_at":"2026-06-17T03:59:05+00:00","first_seen_at":"2026-10-23T19:35:23+00:00","fetched_at":"2026-10-23T19:35:23+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"}