{"id":"CVE-2020-1109","published":"2020-05-21T22:53:10Z","modified":"2026-08-19T16:34:05Z","title":"Windows Update Stack Elevation of Privilege Vulnerability","vendor":"Microsoft","product":"Windows 10 Version 1709","tier":"core","eol":null,"affectedVersions":[{"vendor":"Microsoft","product":"Windows 10 Version 1709","versions":[">= 10.0.0, < publication"]},{"vendor":"Microsoft","product":"Windows 10 Version 1709 for 32-bit Systems","versions":[">= 10.0.0, < publication"]},{"vendor":"Microsoft","product":"Windows 10 Version 1803","versions":[">= 10.0.0, < publication"]},{"vendor":"Microsoft","product":"Windows 10 Version 1809","versions":[">= 10.0.17763.0, < publication"]},{"vendor":"Microsoft","product":"Windows 10 Version 1809","versions":[">= 10.0.0, < publication"]},{"vendor":"Microsoft","product":"Windows 10 Version 1903 for 32-bit Systems","versions":[">= 10.0.0, < publication"]},{"vendor":"Microsoft","product":"Windows 10 Version 1903 for ARM64-based Systems","versions":[">= 10.0.0, < publication"]},{"vendor":"Microsoft","product":"Windows 10 Version 1903 for x64-based Systems","versions":[">= 10.0.0, < publication"]},{"vendor":"Microsoft","product":"Windows 10 Version 1909","versions":[">= 10.0.0, < publication"]},{"vendor":"Microsoft","product":"Windows Server 2019","versions":[">= 10.0.17763.0, < publication"]}],"description":{"text":"An elevation of privilege vulnerability exists when the Windows Update Stack fails to properly handle objects in memory. An attacker who successfully exploited this vulnerability could run arbitrary code in kernel mode. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.\nTo exploit this vulnerability, an attacker would first have to log on to the system. An attacker could then run a specially crafted application to take control of an affected system.\nThe update addresses the vulnerability by correcting how the Windows Update Stack handles objects in memory.","provenance":"source","from":"CVE.org"},"summary":null,"cvss":{"score":7.8,"severity":"HIGH","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C","provenance":"source","from":"CVE.org CNA"},"epss":{"score":0.00994,"percentile":0.62503,"date":"2026-10-28","provenance":"source"},"kev":null,"vulncheckKev":null,"exploited":false,"otx":{"pulseCount":0,"pulses":[],"provenance":"machine"},"cwes":[],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2020-1109","tags":["vendor-advisory","patch"]},{"url":"https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-1109","tags":["x_refsource_MISC","x_transferred"]}],"techniques":[{"id":"T1499.004","name":"Application or System Exploitation","tactics":["impact"],"provenance":"source","basis":"ctid-cve","bases":["ctid-cve"],"basisDetail":"CTID attack_to_cve (Phase 2)","mappingType":"primary_impact","evidence":[],"confidence":"high"},{"id":"T1574","name":"Hijack Execution Flow","tactics":["execution","stealth"],"provenance":"source","basis":"ctid-cve","bases":["ctid-cve"],"basisDetail":"CTID attack_to_cve (Phase 2)","mappingType":"primary_impact","evidence":[],"confidence":"high"},{"id":"T1005","name":"Data from Local System","tactics":["collection"],"provenance":"source","basis":"ctid-cve","bases":["ctid-cve"],"basisDetail":"CTID attack_to_cve (Phase 2)","mappingType":"secondary_impact","evidence":[],"confidence":"high"},{"id":"T1136","name":"Create Account","tactics":["persistence"],"provenance":"source","basis":"ctid-cve","bases":["ctid-cve"],"basisDetail":"CTID attack_to_cve (Phase 2)","mappingType":"secondary_impact","evidence":[],"confidence":"high"},{"id":"T1485","name":"Data Destruction","tactics":["impact"],"provenance":"source","basis":"ctid-cve","bases":["ctid-cve"],"basisDetail":"CTID attack_to_cve (Phase 2)","mappingType":"secondary_impact","evidence":[],"confidence":"high"},{"id":"T1565","name":"Data Manipulation","tactics":["impact"],"provenance":"source","basis":"ctid-cve","bases":["ctid-cve"],"basisDetail":"CTID attack_to_cve (Phase 2)","mappingType":"secondary_impact","evidence":[],"confidence":"high"}],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2020-11996","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2020-11996","exploited":false,"exploitedSince":null,"provenance":"source"},"exploits":[],"exploitSources":null,"exploitRefs":[],"flow":[{"stage":"primary","techniques":["T1574","T1499.004"],"provenance":"source"},{"stage":"secondary","techniques":["T1136","T1005","T1485","T1565"],"provenance":"source"}],"timeline":[{"date":"2020-05-21","kind":"published","label":"Published (CVE.org)","url":"https://www.cve.org/CVERecord?id=CVE-2020-1109","provenance":"source"}],"speed":{"daysToPublicExploit":null,"firstExploitFrom":null,"daysToKev":null},"priority":{"score":18.0,"factors":[{"name":"In a KEV catalog","points":0.0,"detail":"not listed"},{"name":"Recent KEV listing","points":0.0,"detail":"not listed"},{"name":"Known ransomware use","points":0.0,"detail":"not known"},{"name":"EPSS percentile","points":12.5,"detail":"percentile 0.6250"},{"name":"Named in threat reports","points":0.0,"detail":"0 reports"},{"name":"Public exploit code","points":0.0,"detail":"none found"},{"name":"Mentioned in OTX pulses","points":0.0,"detail":"0 pulses"},{"name":"CVSS severity","points":5.46,"detail":"base score 7.8"},{"name":"End-of-life product","points":0.0,"detail":"supported or unknown"}]}}