{"schema":"threatline.record/2","record":{"id":"CVE-2021-43890","aliases":[],"summary":"Microsoft Windows AppX Installer Spoofing Vulnerability","details":"Microsoft Windows AppX Installer contains a spoofing vulnerability which has a high impacts to confidentiality, integrity, and availability.","categories":["Operating systems"],"product":"Windows","vendor":"Microsoft","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2021-43890","source_modified_at":"2026-08-06T03:55:23.978Z","fetched_at":"2026-10-23T18:42:43.628194Z","product":"App Installer","vendor":"Microsoft","versions":[{"version":"1.0.0.0","lessThan":"publication","versionType":"custom","status":"affected"}],"defaultStatus":null}],"fixed_versions":[],"cvss":7.1,"severity":"High","kev":{"listed":true,"date_added":"2021-12-15","due_date":"2021-12-29","required_action":"Apply updates per vendor instructions.","ransomware_campaign_use":"Known"},"epss":{"probability":0.11294,"percentile":0.95974,"score_date":"2026-10-23"},"published_at":"2021-12-15T14:15:35.000Z","modified_at":"2026-08-06T03:55:23.978Z","provenance":[{"source":"CISA KEV","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23T17:00:09.9001Z"},{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2021-43890","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-08-06T03:55:23.978Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2021-43890","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CISA KEV","CVE List","EPSS"],"references":[{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-43890","source":"CISA KEV"},{"source":"CVE List","url":"https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-43890","tags":["x_refsource_MISC","x_transferred"]},{"source":"CVE List","url":"https://www.bleepingcomputer.com/news/microsoft/microsoft-disables-msix-protocol-handler-abused-in-malware-attacks/","tags":["x_transferred"]},{"source":"CVE List","url":"https://thehackernews.com/2023/12/microsoft-disables-msix-app-installer.html","tags":["x_transferred"]},{"source":"CVE List","url":"https://www.microsoft.com/en-us/security/blog/2023/12/28/financially-motivated-threat-actors-misusing-app-installer/","tags":["x_transferred"]},{"source":"CVE List","url":"https://github.com/ChrisTitusTech/winutil/pull/26","tags":["x_transferred"]},{"source":"CVE List","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-43890","tags":["government-resource"]}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","ssvc":{"exploitation":"active","automatable":"no","technical_impact":"total","assessed_at":"2021-12-14T00:00:00+00:00"},"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-08-06T03:55:23.978Z","content_hash":"c00edc53fd3d4ab34adaa33e082a08848ae9e4ba3b356b0712ec2f834a5b8408"}}