{"id":"CVE-2021-28310","published":"2021-04-13T20:15:16Z","modified":"2026-06-17T03:46:08Z","title":"Microsoft Win32k Privilege Escalation Vulnerability","vendor":"Microsoft","product":"Win32k","tier":"core","eol":null,"description":{"text":"Win32k Elevation of Privilege Vulnerability","provenance":"source","from":"NVD"},"summary":{"text":"The flaw is a Win32k elevation of privilege vulnerability in Microsoft's Win32k component, classified as an out-of-bounds write. An attacker with local access and low-privileged credentials, requiring no user interaction, can exploit it to gain elevated privileges with high impact on confidentiality, integrity and availability.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-23T07:11:32Z"},"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","provenance":"source","from":"NVD"},"epss":{"score":0.08398,"percentile":0.94969,"date":"2026-10-29","provenance":"source"},"kev":{"dateAdded":"2021-11-03","dueDate":"2021-11-17","ransomware":false,"requiredAction":"Apply updates per vendor instructions.","notes":"https://nvd.nist.gov/vuln/detail/CVE-2021-28310","provenance":"source"},"vulncheckKev":{"dateAdded":"2021-04-13","exploitedFirstSeen":"2021-04-13","ransomware":false,"evidence":[{"url":"https://api.msrc.microsoft.com/cvrf/v3.0/cvrf/2021-Apr","date":"2021-04-13"},{"url":"https://docs.google.com/spreadsheets/d/1lkNJ0uQwbeC1ZTRrxdtuPLCIl7mlUreoKfSIgajnSyY/edit","date":"2021-04-13"},{"url":"https://securelist.com/zero-day-vulnerability-in-desktop-window-manager-cve-2021-28310-used-in-the-wild/101898/","date":"2021-04-13"},{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2021-11-03"},{"url":"https://www.secuinfra.com/en/techtalk/whatever-floats-your-boat-bitter-apt-continues-to-target-bangladesh/","date":"2022-05-07"},{"url":"https://blog.talosintelligence.com/2022/05/bitter-apt-adds-bangladesh-to-their.html","date":"2022-05-12"},{"url":"https://www.ptsecurity.com/ww-en/analytics/apt-groups-in-the-middle-east/","date":"2024-03-27"},{"url":"https://pt-global.storage.yandexcloud.net/positive_research_2024_a9c4fb10c2.pdf","date":"2024-10-16"}],"evidenceTotal":8,"provenance":"source"},"exploited":true,"otx":{"pulseCount":50,"pulses":[{"name":"Actively_Exploited_Kev | Oct 29, 2026","url":"https://otx.alienvault.com/pulse/6ae20c1db17e7057ae7d9ad1","created":"2026-10-28"},{"name":"Actively_Exploited_Kev | Oct 28, 2026","url":"https://otx.alienvault.com/pulse/6ae0ba7e0e2a97ff7b218819","created":"2026-10-27"},{"name":"Actively_Exploited_Kev | Oct 27, 2026","url":"https://otx.alienvault.com/pulse/6adf68b85c3e852f3c111d18","created":"2026-10-26"},{"name":"Actively_Exploited_Kev | Oct 24, 2026","url":"https://otx.alienvault.com/pulse/6adb740e397c3ad4799aa4cd","created":"2026-10-23"},{"name":"Actively_Exploited_Kev | Oct 23, 2026","url":"https://otx.alienvault.com/pulse/6ada236fcfba2dfa730ea482","created":"2026-10-22"},{"name":"Actively_Exploited_Kev | Oct 22, 2026","url":"https://otx.alienvault.com/pulse/6ad8d33a077cbb5cab524d80","created":"2026-10-21"},{"name":"Actively_Exploited_Kev | Oct 21, 2026","url":"https://otx.alienvault.com/pulse/6ad78130c4d1ac2be83a8b6d","created":"2026-10-20"},{"name":"Actively_Exploited_Kev | Oct 20, 2026","url":"https://otx.alienvault.com/pulse/6ad62f63c24a405a3423cc13","created":"2026-10-19"},{"name":"Actively_Exploited_Kev | Oct 19, 2026","url":"https://otx.alienvault.com/pulse/6ad4dda174e5797d0bd238b7","created":"2026-10-18"},{"name":"Actively_Exploited_Kev | Oct 18, 2026","url":"https://otx.alienvault.com/pulse/6ad38c22e1848f8189d1c121","created":"2026-10-17"}],"provenance":"machine"},"cwes":[{"id":"CWE-787","name":"Out-of-bounds Write"}],"references":[{"url":"https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-28310","tags":["Patch","Vendor Advisory"]},{"url":"https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-28310","tags":["Patch","Vendor Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-28310","tags":["US Government Resource"]}],"techniques":[{"id":"T1068","name":"Exploitation for Privilege Escalation","tactics":["privilege-escalation"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: Local privilege escalation vulnerability in kernel component","mappingType":"exploitation_technique","evidence":[{"from":"description","quote":"Win32k Elevation of Privilege Vulnerability","start":0,"end":43}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"}],"reports":[{"id":"SRC-c25100ad56d1b485f562","title":"Bitter APT adds Bangladesh to their targets","publisher":"blog.talosintelligence.com","url":"https://blog.talosintelligence.com/bitter-apt-adds-bangladesh-to-their/","date":"2022-05-11","mentions":[{"quote":"For example, in 2021, security researchers discovered that the adversary was exploiting the zero-day vulnerability CVE-2021-28310, a security flaw in Microsoft's Desktop Manager.","start":2678,"end":2856}]}],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2021-14995","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2021-14995","exploited":true,"exploitedSince":"2021-11-03","provenance":"source"},"exploits":[],"exploitSources":{"pocGithub":{"count":1,"skipped":0,"earliest":"2021-04-14","earliestUrl":"https://github.com/Rafael-Svechinskaya/IOC_for_CVE-2021-28310","repos":[{"name":"Rafael-Svechinskaya/IOC_for_CVE-2021-28310","url":"https://github.com/Rafael-Svechinskaya/IOC_for_CVE-2021-28310","stars":0,"created":"2021-04-14"}]},"first":{"date":"2021-04-14","source":"PoC-in-GitHub","url":"https://github.com/Rafael-Svechinskaya/IOC_for_CVE-2021-28310"},"provenance":"source"},"exploitRefs":[],"flow":[{"stage":"exploitation","techniques":["T1068"],"provenance":"ai"}],"timeline":[{"date":"2021-04-13","kind":"published","label":"Published 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