{"id":"CVE-2025-32709","kind":"vulnerability","aliases":["CVE-2025-32709"],"related":[],"title":"Null pointer dereference in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate…","description":"Microsoft Windows Ancillary Function Driver for WinSock contains a use-after-free vulnerability that allows an authorized attacker to escalate privileges to administrator.\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":"A use-after-free bug in the Windows Ancillary Function Driver for WinSock (afd.sys) lets a logged-in user corrupt memory in the kernel. An attacker who already has a local foothold can escalate to administrator.","severity":"high","cvss":7.8,"epss":null,"exploited":true,"exploited_at":"2025-05-13T00:00:00+00:00","products":[{"name":"Microsoft Windows","fixed":[],"affected":"","ecosystem":"vendor"},{"name":"microsoft windows 10 1507","fixed":["10.0.10240.21014"],"affected":"< 10.0.10240.21014","ecosystem":"vendor"},{"name":"microsoft windows 10 1607","fixed":["10.0.14393.8066"],"affected":"< 10.0.14393.8066","ecosystem":"vendor"},{"name":"microsoft windows 10 1809","fixed":["10.0.17763.7314"],"affected":"< 10.0.17763.7314","ecosystem":"vendor"},{"name":"microsoft windows 10 21h2","fixed":["10.0.19044.5854"],"affected":"< 10.0.19044.5854","ecosystem":"vendor"},{"name":"microsoft windows 10 22h2","fixed":["10.0.19045.5854"],"affected":"< 10.0.19045.5854","ecosystem":"vendor"},{"name":"microsoft windows 11 22h2","fixed":["10.0.22621.5335"],"affected":"< 10.0.22621.5335","ecosystem":"vendor"},{"name":"microsoft windows 11 23h2","fixed":["10.0.22631.5335"],"affected":"< 10.0.22631.5335","ecosystem":"vendor"},{"name":"microsoft windows 11 24h2","fixed":["10.0.26100.3981"],"affected":"< 10.0.26100.3981","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":["10.0.14393.8066"],"affected":"< 10.0.14393.8066","ecosystem":"vendor"},{"name":"microsoft windows server 2019","fixed":["10.0.17763.7314"],"affected":"< 10.0.17763.7314","ecosystem":"vendor"},{"name":"microsoft windows server 2022","fixed":["10.0.20348.3692"],"affected":"< 10.0.20348.3692","ecosystem":"vendor"},{"name":"microsoft windows server 2022 23h2","fixed":["10.0.25398.1611"],"affected":"< 10.0.25398.1611","ecosystem":"vendor"},{"name":"microsoft windows server 2025","fixed":["10.0.26100.3981"],"affected":"< 10.0.26100.3981","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["exploited","infrastructure","self-hosted","windows"],"not_affected_if":["no-local-user-access"],"how_to_check":null,"fix":"Apply the Microsoft security update for CVE-2025-32709 per vendor instructions; CISA says to follow vendor mitigations or discontinue use if none are available.","status":"open","published_at":"2025-05-13T00:00:00+00:00","first_seen_at":"2026-10-23T19:11:51+00:00","triaged_at":"2026-10-23T20:48:37+00:00","updated_at":"2026-10-23T22:29:05+00:00","category":"infrastructure","confidence":0.7,"triage":{"at":"2026-10-23T20:48:37Z","model":"claude-haiku-5-5","output":{"fix":"Apply the Microsoft security update for CVE-2025-32709 per vendor instructions; CISA says to follow vendor mitigations or discontinue use if none are available.\nunknown","reach":"local","summary":"A use-after-free bug in the Windows Ancillary Function Driver for WinSock (afd.sys) lets a logged-in user corrupt memory in the kernel. An attacker who already has a local foothold can escalate to administrator.","category":"infrastructure","who_cares":["windows","self-hosted"],"confidence":0.7,"needs_auth":"yes","worst_case":"Local attacker gains administrator rights on the Windows machine.","analyst_note":"Confirm the fixed Windows build numbers and the exact patch KB from Microsoft's CVE-2025-32709 advisory; the sources give no version or check command.","how_to_check":"unknown","needs_analyst":true,"not_affected_if":["no-local-user-access"],"user_interaction":"no","needs_special_setup":"no","severity_if_unknown":"high"},"cost_usd":0.000435,"input_tokens":2549,"output_tokens":361,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-01':174C '-2025':18A,21A '-32709':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':173C '22h2':44A,48A '23h2':52A,89A '24h2':56A 'action':164C 'administr':137B,161C 'afd.sys':114B 'allow':11A,153C 'alreadi':129B 'ancillari':6A,109B,140C 'appli':165C 'applic':171C 'attack':14A,127B,156C 'author':13A,155C 'bod':172C 'bug':105B 'cisa':162C 'cloud':177C 'contain':145C 'corrupt':121B 'cve':17A,20A 'derefer':3A 'discontinu':180C 'driver':8A,111B,142C 'elev':16A 'escal':135B,158C 'exploit':94B 'follow':170C 'foothold':133B 'free':104B,150C 'function':7A,110B,141C 'guidanc':175C 'host':98B 'infrastructur':95B 'instruct':169C 'kernel':125B 'let':115B 'local':132B 'log':118B 'logged-in':117B 'memori':122B 'microsoft':23A,25A,29A,33A,37A,41A,45A,49A,53A,57A,61A,65A,69A,73A,77A,81A,85A,90A,138C 'mitig':166C,186C 'null':1A 'per':167C 'pointer':2A 'privileg':159C 'product':184C 'requir':163C 'self':97B 'self-host':96B 'server':59A,63A,67A,71A,75A,79A,83A,87A,92A 'servic':178C 'unavail':188C 'use':102B,148C,181C 'use-after-fre':101B,147C 'user':120B 'vendor':168C 'vulner':151C 'window':5A,99B,108B,139C 'windows':24A,26A,30A,34A,38A,42A,46A,50A,54A,58A,62A,66A,70A,74A,78A,82A,86A,91A 'winsock':10A,113B,144C","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2025-05-13T00:00:00+00:00","kev":{"dateAdded":"2025-05-13","dueDate":"2025-06-03","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:L/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-2025-32709","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2025-32709","severity":null,"published_at":"2025-05-13T00:00:00+00:00","modified_at":null,"first_seen_at":"2026-10-23T19:11:51+00:00","fetched_at":"2026-10-25T15:39:40+00:00","note":null},{"source":"nvd","external_id":"CVE-2025-32709","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-32709","severity":null,"published_at":"2025-05-13T17:16:04+00:00","modified_at":"2026-06-17T09:12:27+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"}