{"id":"CVE-2011-2005","kind":"vulnerability","aliases":["CVE-2011-2005"],"related":[],"title":"Microsoft Ancillary Function Driver (afd.sys): Microsoft Ancillary Function Driver (afd.sys) Improper Input Validation Vulnerability","description":"afd.sys in the Ancillary Function Driver in Microsoft Windows XP SP2 and SP3 and Server 2003 SP2 does not properly validate user-mode input passed to kernel mode, which allows local users to gain privileges via a crafted application, aka \"Ancillary Function Driver Elevation of Privilege Vulnerability.\"","summary":"Microsoft Windows afd.sys, the kernel driver behind Winsock socket calls, does not validate user-mode input passed to kernel mode. A local user running a crafted application can escalate to kernel-level privileges.","severity":"high","cvss":7.8,"epss":0.31761,"exploited":true,"exploited_at":"2022-03-28T00:00:00+00:00","products":[{"name":"Microsoft Ancillary Function Driver (afd.sys)","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["exploited","infrastructure","multi-user-hosts","terminal-servers","windows"],"not_affected_if":["non-windows","patched-windows"],"how_to_check":null,"fix":"Apply the Microsoft updates for this CVE per vendor instructions, as CISA requires; the sources do not name the specific patch or KB.","status":"open","published_at":"2011-10-12T02:52:43+00:00","first_seen_at":"2026-10-23T19:11:52+00:00","triaged_at":"2026-10-23T21:19:56+00:00","updated_at":"2026-10-23T21:57:35+00:00","category":"infrastructure","confidence":0.8,"triage":{"at":"2026-10-23T21:19:56Z","model":"claude-haiku-5-5","output":{"fix":"Apply the Microsoft updates for this CVE per vendor instructions, as CISA requires; the sources do not name the specific patch or KB.","reach":"local","impact":"high","summary":"Microsoft Windows afd.sys, the kernel driver behind Winsock socket calls, does not validate user-mode input passed to kernel mode. A local user running a crafted application can escalate to kernel-level privileges.","category":"infrastructure","who_cares":["windows","multi-user-hosts","terminal-servers"],"confidence":0.8,"needs_auth":"yes","worst_case":"Local user gains kernel privileges and full control of the Windows machine.","analyst_note":"Find the Microsoft security bulletin for CVE-2011-2005 and the affected Windows versions and KB numbers, since the sources give no fixed-version details.","how_to_check":"unknown","needs_analyst":true,"not_affected_if":["patched-windows","non-windows"],"user_interaction":"no","needs_special_setup":"no","severity_if_unknown":"high"},"cost_usd":0.00047,"input_tokens":2883,"output_tokens":363,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2005':17A,20A '-2011':16A,19A '2003':86C 'afd.sys':5A,10A,25A,38B,71C 'aka':111C 'allow':101C 'ancillari':2A,7A,74C,112C 'ancillary':22A 'applic':63B,110C 'behind':42B 'call':45B 'craft':62B,109C 'cve':15A,18A 'driver':4A,9A,24A,41B,76C,114C 'elev':115C 'escal':65B 'exploit':26B 'function':3A,8A,23A,75C,113C 'gain':105C 'host':31B 'improp':11A 'infrastructur':27B 'input':12A,52B,95C 'kernel':40B,55B,68B,98C 'kernel-level':67B 'level':69B 'local':58B,102C 'microsoft':1A,6A,21A,36B,78C 'mode':51B,56B,94C,99C 'multi':29B 'multi-user-host':28B 'pass':53B,96C 'privileg':70B,106C,117C 'proper':90C 'run':60B 'server':34B,85C 'socket':44B 'sp2':81C,87C 'sp3':83C 'termin':33B 'terminal-serv':32B 'user':30B,50B,59B,93C,103C 'user-mod':49B,92C 'valid':13A,48B,91C 'via':107C 'vulner':14A,118C 'window':35B,37B,79C 'winsock':43B 'xp':80C","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2011-10-12T02:52:43+00:00","kev":{"dateAdded":"2022-03-28","dueDate":"2022-04-18","requiredAction":"Apply updates per vendor instructions.","knownRansomwareCampaignUse":"Unknown"},"cvss_vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","cvss_by":"nvd@nist.gov","poc_count":0,"sources":[{"source":"kev","external_id":"CVE-2011-2005","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2011-2005","severity":null,"published_at":"2022-03-28T00:00:00+00:00","modified_at":null,"first_seen_at":"2026-10-23T19:11:52+00:00","fetched_at":"2026-10-25T16:39:48+00:00","note":null},{"source":"epss","external_id":"CVE-2011-2005","url":"https://api.first.org/data/v1/epss?cve=CVE-2011-2005","severity":null,"published_at":null,"modified_at":null,"first_seen_at":"2026-10-23T19:13:45+00:00","fetched_at":"2026-10-23T19:13:45+00:00","note":null},{"source":"nvd","external_id":"CVE-2011-2005","url":"https://nvd.nist.gov/vuln/detail/CVE-2011-2005","severity":null,"published_at":"2011-10-12T02:52:43+00:00","modified_at":"2026-06-16T23:30:35+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"}