{"id":"CVE-2025-21333","published":"2025-01-14T18:15:58Z","modified":"2026-06-17T08:43:07Z","title":"Microsoft Windows Hyper-V NT Kernel Integration VSP Heap-based Buffer Overflow Vulnerability","vendor":"Microsoft","product":"Windows","tier":"core","eol":null,"description":{"text":"Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege Vulnerability","provenance":"source","from":"NVD"},"summary":{"text":"A heap-based buffer overflow in the Hyper-V NT Kernel Integration VSP component of Microsoft Windows allows privilege escalation. An attacker needs local access with low-privilege authenticated credentials, and no user interaction is required.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-23T07:11:17Z"},"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":0.10066,"percentile":0.95615,"date":"2026-10-29","provenance":"source"},"kev":{"dateAdded":"2025-01-14","dueDate":"2025-02-04","ransomware":false,"requiredAction":"Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.","notes":"https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2025-21333 ; https://nvd.nist.gov/vuln/detail/CVE-2025-21333","provenance":"source"},"vulncheckKev":{"dateAdded":"2025-01-14","exploitedFirstSeen":"2025-01-14","ransomware":false,"evidence":[{"url":"https://api.msrc.microsoft.com/cvrf/v3.0/cvrf/2025-Jan","date":"2025-01-14"},{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21333","date":"2025-01-14"},{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2025-01-14"},{"url":"https://securelist.com/vulnerabilities-and-exploits-in-q1-2025/116624/","date":"2025-05-30"},{"url":"https://www.kelacyber.com/resources/research/2025_midyear_threat_report/","date":"2025-08-08"},{"url":"https://www.loginsoft.com/reports/annually/vulnerability-intelligence-report-2025","date":"2026-01-20"},{"url":"https://www.ussc.ru/upload/files/%D0%9E%D1%82%D1%87%D0%B5%D1%82%20SOC.pdf","date":"2026-06-03"}],"evidenceTotal":7,"provenance":"source"},"exploited":true,"otx":{"pulseCount":50,"pulses":[{"name":"Actively_Exploited_Kev | Oct 30, 2026","url":"https://otx.alienvault.com/pulse/6ae35d889ea92b4ce19c2680","created":"2026-10-29"},{"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"}],"provenance":"machine"},"cwes":[{"id":"CWE-122","name":"Heap-based Buffer Overflow"}],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21333","tags":["Patch","Vendor Advisory"]},{"url":"https://www.exploit-db.com/exploits/52436","tags":["Exploit","Third Party Advisory","VDB Entry"]},{"url":"https://www.vicarius.io/vsociety/posts/cve-2025-21333-elevated-privilege-exposure-in-windows-hyper-v-by-microsoft-detection-script","tags":["Mitigation","Third Party Advisory"]},{"url":"https://www.vicarius.io/vsociety/posts/cve-2025-21333-elevated-privilege-exposure-in-windows-hyper-v-by-microsoft-mitigation-script","tags":["Mitigation","Third Party Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-21333","tags":["US Government Resource"]}],"techniques":[{"id":"T1068","name":"Exploitation for Privilege Escalation","tactics":["privilege-escalation"],"provenance":"source","basis":"ctid-kev","bases":["ctid-kev"],"basisDetail":"CTID Mappings Explorer KEV 07/28/2025 (ATT&CK 16.1); capability: Buffer Overflow","mappingType":"exploitation_technique","evidence":[],"comment":"This vulnerability, if exploited, would allow an adversary to obtain SYSTEM-level privileges, resulting in total system compromise.","confidence":"high"},{"id":"T1003","name":"OS Credential Dumping","tactics":["credential-access"],"provenance":"source","basis":"ctid-kev","bases":["ctid-kev"],"basisDetail":"CTID Mappings Explorer KEV 07/28/2025 (ATT&CK 16.1); capability: Buffer Overflow","mappingType":"primary_impact","evidence":[],"comment":"This vulnerability, if exploited, would allow an adversary to obtain SYSTEM-level privileges, resulting in total system compromise.","confidence":"high"}],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2025-2398","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2025-2398","exploited":true,"exploitedSince":"2025-01-14","provenance":"source"},"exploits":[{"id":52436,"url":"https://www.exploit-db.com/exploits/52436","title":"Microsoft Windows Server 2025 Hyper-V NT Kernel Integration VSP - Elevation of Privilege","type":"local","platform":"windows","date":"2025-09-16","verified":false,"provenance":"source"}],"exploitSources":{"exploitdb":{"count":1,"earliest":"2025-09-16"},"pocGithub":{"count":3,"skipped":1,"earliest":"2025-02-27","earliestUrl":"https://github.com/MrAle98/CVE-2025-21333-POC","repos":[{"name":"MrAle98/CVE-2025-21333-POC","url":"https://github.com/MrAle98/CVE-2025-21333-POC","stars":232,"created":"2025-02-27"},{"name":"nu1lptr0/CVE-2025-21333","url":"https://github.com/nu1lptr0/CVE-2025-21333","stars":23,"created":"2026-05-05"},{"name":"aleongx/KQL_sentinel_CVE-2025-21333","url":"https://github.com/aleongx/KQL_sentinel_CVE-2025-21333","stars":0,"created":"2025-03-11"}]},"first":{"date":"2025-02-27","source":"PoC-in-GitHub","url":"https://github.com/MrAle98/CVE-2025-21333-POC"},"provenance":"source"},"exploitRefs":["https://www.exploit-db.com/exploits/52436"],"flow":[{"stage":"exploitation","techniques":["T1068"],"provenance":"source"},{"stage":"primary","techniques":["T1003"],"provenance":"source"}],"timeline":[{"date":"2025-01-14","kind":"published","label":"Published (NVD)","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-21333","provenance":"source"},{"date":"2025-01-14","kind":"exploited-reported","label":"Exploitation first reported (VulnCheck KEV evidence)","url":"https://api.msrc.microsoft.com/cvrf/v3.0/cvrf/2025-Jan","provenance":"source"},{"date":"2025-01-14","kind":"kev","label":"Added to CISA KEV","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","provenance":"source"},{"date":"2025-01-14","kind":"euvd-exploited","label":"ENISA EUVD: exploited","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2025-2398","provenance":"source"},{"date":"2025-02-27","kind":"exploit-public","label":"First public exploit: PoC-in-GitHub; 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