{"id":"CVE-2024-21351","kind":"vulnerability","aliases":["CVE-2024-21351"],"related":[],"title":"Windows SmartScreen Security Feature Bypass Vulnerability","description":"Microsoft Windows SmartScreen contains a security feature bypass vulnerability that allows an attacker to bypass the SmartScreen user experience and inject code to potentially gain code execution, which could lead to some data exposure, lack of system availability, or both.\n\nCISA required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.","summary":"Microsoft Windows SmartScreen has a security feature bypass that lets an attacker get past its user warnings and inject code. The attacker can then potentially run code, expose some data, or disrupt the system.","severity":"high","cvss":7.6,"epss":null,"exploited":true,"exploited_at":"2024-02-13T00:00:00+00:00","products":[{"name":"Microsoft Windows","fixed":[],"affected":"","ecosystem":"vendor"},{"name":"microsoft windows 10 1507","fixed":["10.0.10240.20469"],"affected":"< 10.0.10240.20469","ecosystem":"vendor"},{"name":"microsoft windows 10 1607","fixed":["10.0.14393.6709"],"affected":"< 10.0.14393.6709","ecosystem":"vendor"},{"name":"microsoft windows 10 1809","fixed":["10.0.17763.5458"],"affected":"< 10.0.17763.5458","ecosystem":"vendor"},{"name":"microsoft windows 10 21h2","fixed":["10.0.19044.4046"],"affected":"< 10.0.19044.4046","ecosystem":"vendor"},{"name":"microsoft windows 10 22h2","fixed":["10.0.19045.4046"],"affected":"< 10.0.19045.4046","ecosystem":"vendor"},{"name":"microsoft windows 11 21h2","fixed":["10.0.22000.2777"],"affected":"< 10.0.22000.2777","ecosystem":"vendor"},{"name":"microsoft windows 11 22h2","fixed":["10.0.22621.3155"],"affected":"< 10.0.22621.3155","ecosystem":"vendor"},{"name":"microsoft windows 11 23h2","fixed":["10.0.22631.3155"],"affected":"< 10.0.22631.3155","ecosystem":"vendor"},{"name":"microsoft windows server 2016","fixed":[],"affected":"","ecosystem":"vendor"},{"name":"microsoft windows server 2019","fixed":["10.0.17763.5458"],"affected":"< 10.0.17763.5458","ecosystem":"vendor"},{"name":"microsoft windows server 2022","fixed":["10.0.20348.2322"],"affected":"< 10.0.20348.2322","ecosystem":"vendor"},{"name":"microsoft windows server 2022 23h2","fixed":["10.0.25398.709"],"affected":"< 10.0.25398.709","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["endpoints","exploited","infrastructure","windows"],"not_affected_if":["unknown"],"how_to_check":null,"fix":"Apply the mitigations per Microsoft's vendor instructions, or discontinue use of the affected product if mitigations are unavailable (CISA required action).","status":"open","published_at":"2024-02-13T00:00:00+00:00","first_seen_at":"2026-10-23T19:11:51+00:00","triaged_at":"2026-10-23T21:02:21+00:00","updated_at":"2026-10-23T22:29:05+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-10-23T21:02:21Z","model":"claude-haiku-5-5","output":{"fix":"Apply the mitigations per Microsoft's vendor instructions, or discontinue use of the affected product if mitigations are unavailable (CISA required action).","reach":"unknown","impact":"high","summary":"Microsoft Windows SmartScreen has a security feature bypass that lets an attacker get past its user warnings and inject code. The attacker can then potentially run code, expose some data, or disrupt the system.","category":"infrastructure","who_cares":["windows","endpoints"],"confidence":0.6,"needs_auth":"unknown","worst_case":"Attacker runs injected code on the Windows machine, potentially exposing data.","analyst_note":"Sources lack patch version, detection steps and exploit vector; check Microsoft's CVE-2024-21351 security update guide entry and the CISA KEV listing for mitigation details.","how_to_check":"unknown","needs_analyst":true,"not_affected_if":["unknown"],"user_interaction":"yes","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000465,"input_tokens":2850,"output_tokens":359,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2024':8A,11A '-21351':9A,12A '10':17A,21A,25A,29A,33A '11':37A,41A,45A '1507':18A '1607':22A '1809':26A '2016':50A '2019':54A '2022':58A,62A '21h2':30A,38A '22h2':34A,42A '23h2':46A,63A 'action':144C 'allow':112C 'appli':145C 'attack':79B,89B,114C 'avail':139C 'bypass':5A,75B,109C,116C 'cisa':142C 'code':87B,94B,123C,127C 'contain':105C 'could':130C 'cve':7A,10A 'data':97B,134C 'discontinu':151C 'disrupt':99B 'endpoint':64B 'execut':128C 'experi':120C 'exploit':65B 'expos':95B 'exposur':135C 'featur':4A,74B,108C 'gain':126C 'get':80B 'infrastructur':66B 'inject':86B,122C 'instruct':149C 'lack':136C 'lead':131C 'let':77B 'microsoft':13A,15A,19A,23A,27A,31A,35A,39A,43A,47A,51A,55A,59A,68B,102C 'mitig':146C,157C 'past':81B 'per':147C 'potenti':92B,125C 'product':155C 'requir':143C 'run':93B 'secur':3A,73B,107C 'server':49A,53A,57A,61A 'smartscreen':2A,70B,104C,118C 'system':101B,138C 'unavail':159C 'use':152C 'user':83B,119C 'vendor':148C 'vulner':6A,110C 'warn':84B 'window':1A,67B,69B,103C 'windows':14A,16A,20A,24A,28A,32A,36A,40A,44A,48A,52A,56A,60A","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2024-02-13T00:00:00+00:00","kev":{"dateAdded":"2024-02-13","dueDate":"2024-03-05","requiredAction":"Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.","knownRansomwareCampaignUse":"Unknown"},"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:L","cvss_by":"secure@microsoft.com","poc_count":0,"sources":[{"source":"kev","external_id":"CVE-2024-21351","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2024-21351","severity":null,"published_at":"2024-02-13T00:00:00+00:00","modified_at":null,"first_seen_at":"2026-10-23T19:11:51+00:00","fetched_at":"2026-10-25T20:35:34+00:00","note":null},{"source":"nvd","external_id":"CVE-2024-21351","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-21351","severity":null,"published_at":"2024-02-13T18:15:51+00:00","modified_at":"2026-08-10T16:18:42+00:00","first_seen_at":"2026-10-23T22:29:05+00:00","fetched_at":"2026-10-23T22:29:05+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"}