{"id":"CVE-2025-33073","kind":"vulnerability","aliases":["CVE-2025-33073"],"related":[],"title":"Improper access control in Windows SMB allows an authorized attacker to elevate privileges over a network","description":"Microsoft Windows SMB Client contains an improper access control vulnerability that could allow for privilege escalation. An attacker could execute a specially crafted malicious script to coerce the victim machine to connect back to the attack system using SMB and authenticate.\n\nCISA required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.","summary":"Windows SMB client has an improper access control flaw that lets an attacker escalate privileges on a Windows machine. A crafted script can make the victim machine connect back over SMB and authenticate to the attacker, which can expose credentials for relay or theft.","severity":"high","cvss":8.8,"epss":null,"exploited":true,"exploited_at":"2025-10-20T00:00:00+00:00","products":[{"name":"Microsoft Windows","fixed":[],"affected":"","ecosystem":"vendor"},{"name":"microsoft windows 10 1507","fixed":["10.0.10240.21034"],"affected":"< 10.0.10240.21034","ecosystem":"vendor"},{"name":"microsoft windows 10 1607","fixed":["10.0.14393.8148"],"affected":"< 10.0.14393.8148","ecosystem":"vendor"},{"name":"microsoft windows 10 1809","fixed":["10.0.17763.7434"],"affected":"< 10.0.17763.7434","ecosystem":"vendor"},{"name":"microsoft windows 10 21h2","fixed":["10.0.19044.5965"],"affected":"< 10.0.19044.5965","ecosystem":"vendor"},{"name":"microsoft windows 10 22h2","fixed":["10.0.19045.5965"],"affected":"< 10.0.19045.5965","ecosystem":"vendor"},{"name":"microsoft windows 11 22h2","fixed":["10.0.22621.5472"],"affected":"< 10.0.22621.5472","ecosystem":"vendor"},{"name":"microsoft windows 11 23h2","fixed":["10.0.22631.5472"],"affected":"< 10.0.22631.5472","ecosystem":"vendor"},{"name":"microsoft windows 11 24h2","fixed":["10.0.26100.4270"],"affected":"< 10.0.26100.4270","ecosystem":"vendor"},{"name":"microsoft windows server 2008","fixed":[],"affected":"","ecosystem":"vendor"},{"name":"microsoft windows server 2008","fixed":[],"affected":"= r2","ecosystem":"vendor"},{"name":"microsoft windows server 2012","fixed":[],"affected":"","ecosystem":"vendor"},{"name":"microsoft windows server 2012","fixed":[],"affected":"= r2","ecosystem":"vendor"},{"name":"microsoft windows server 2016","fixed":["10.0.14393.8148"],"affected":"< 10.0.14393.8148","ecosystem":"vendor"},{"name":"microsoft windows server 2019","fixed":["10.0.17763.7434"],"affected":"< 10.0.17763.7434","ecosystem":"vendor"},{"name":"microsoft windows server 2022","fixed":["10.0.20348.3745"],"affected":"< 10.0.20348.3745","ecosystem":"vendor"},{"name":"microsoft windows server 2022 23h2","fixed":["10.0.25398.1665"],"affected":"< 10.0.25398.1665","ecosystem":"vendor"},{"name":"microsoft windows server 2025","fixed":["10.0.26100.4270"],"affected":"< 10.0.26100.4270","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["active-directory","exploited","infrastructure","smb","windows"],"not_affected_if":["unknown"],"how_to_check":null,"fix":"Apply the Microsoft mitigations for CVE-2025-33073 and install the current Windows security update; the exact patch version is not in the sources.","status":"open","published_at":"2025-06-10T17:23:02+00:00","first_seen_at":"2026-10-23T19:11:51+00:00","triaged_at":"2026-10-23T20:44:30+00:00","updated_at":"2026-10-23T23:44:51+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-10-23T20:44:30Z","model":"claude-haiku-5-5","output":{"fix":"Apply the Microsoft mitigations for CVE-2025-33073 and install the current Windows security update; the exact patch version is not in the sources.","reach":"network","summary":"Windows SMB client has an improper access control flaw that lets an attacker escalate privileges on a Windows machine. A crafted script can make the victim machine connect back over SMB and authenticate to the attacker, which can expose credentials for relay or theft.","category":"infrastructure","who_cares":["windows","smb","active-directory"],"confidence":0.6,"needs_auth":"unknown","worst_case":"Attacker gains elevated privileges on a Windows machine and can capture or relay SMB credentials.","analyst_note":"Find the Microsoft MSRC advisory for CVE-2025-33073 for affected Windows builds, the patch KB, and the specific mitigation steps; the sources do not give them.","how_to_check":"unknown","needs_analyst":true,"not_affected_if":["unknown"],"user_interaction":"yes","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000443,"input_tokens":2563,"output_tokens":374,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-01':198C '-2025':18A,21A '-33073':19A,22A '10':27A,31A,35A,39A,43A '11':47A,51A,55A '1507':28A '1607':32A '1809':36A '2008':60A,64A '2012':68A,72A '2016':76A '2019':80A '2022':84A,88A '2025':93A '21h2':40A '22':197C '22h2':44A,48A '23h2':52A,89A '24h2':56A 'access':2A,107B,152C 'action':188C 'activ':95B 'active-directori':94B 'allow':7A,157C 'appli':189C 'applic':195C 'attack':10A,113B,136B,162C,180C 'authent':133B,185C 'author':9A 'back':129B,177C 'bod':196C 'cisa':186C 'client':103B,148C 'cloud':201C 'coerc':171C 'connect':128B,176C 'contain':149C 'control':3A,108B,153C 'could':156C,163C 'craft':121B,167C 'credenti':140B 'cve':17A,20A 'directori':96B 'discontinu':204C 'elev':12A 'escal':114B,160C 'execut':164C 'exploit':97B 'expos':139B 'flaw':109B 'follow':194C 'guidanc':199C 'improp':1A,106B,151C 'infrastructur':98B 'instruct':193C 'let':111B 'machin':119B,127B,174C 'make':124B 'malici':168C 'microsoft':23A,25A,29A,33A,37A,41A,45A,49A,53A,57A,61A,65A,69A,73A,77A,81A,85A,90A,145C 'mitig':190C,210C 'network':16A 'per':191C 'privileg':13A,115B,159C 'product':208C 'relay':142B 'requir':187C 'script':122B,169C 'server':59A,63A,67A,71A,75A,79A,83A,87A,92A 'servic':202C 'smb':6A,99B,102B,131B,147C,183C 'special':166C 'system':181C 'theft':144B 'unavail':212C 'use':182C,205C 'vendor':192C 'victim':126B,173C 'vulner':154C 'window':5A,100B,101B,118B,146C 'windows':24A,26A,30A,34A,38A,42A,46A,50A,54A,58A,62A,66A,70A,74A,78A,82A,86A,91A","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2025-06-10T17:23:02+00:00","kev":{"dateAdded":"2025-10-20","dueDate":"2025-11-10","requiredAction":"Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.","knownRansomwareCampaignUse":"Unknown"},"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvss_by":"secure@microsoft.com","poc_count":0,"sources":[{"source":"kev","external_id":"CVE-2025-33073","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2025-33073","severity":null,"published_at":"2025-10-20T00:00:00+00:00","modified_at":null,"first_seen_at":"2026-10-23T19:11:51+00:00","fetched_at":"2026-10-25T16:39:45+00:00","note":null},{"source":"nvd","external_id":"CVE-2025-33073","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-33073","severity":null,"published_at":"2025-06-10T17:23:02+00:00","modified_at":"2026-06-17T09:13:04+00:00","first_seen_at":"2026-10-23T23:44:51+00:00","fetched_at":"2026-10-23T23:44:51+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"}